Renee Fitzgerald has been on Tasmania's social housing waiting list for four years. She works three shifts a week in aged care, pays $420 a week for a mould-affected rental in Hobart's northern suburbs, and calls the state housing department every year to ask where her application sits. In February 2023, for the first time in a long while, she had reason to hope the wait might shorten. The federal government introduced legislation for a $10 billion fund that promised thousands of new social and affordable homes, some of them in Tasmania. Then nothing happened. For roughly seven months, the bill sat blocked in the Senate — not by the Coalition alone, but by the Greens, who argued the fund was not ambitious enough and wanted a national freeze on rent increases attached before they would let it pass. Renee did not vote for the Greens or against them in any sense that mattered to her file. She just kept paying rent on a home with damp in the ceiling, waiting for a number on a list to move, while two blocs in Canberra argued over how ambitious a housing fund needed to be before either of them would let it become law.
That seven-month stand-off is a small, human-scale window into a much bigger feature of Australian politics since 2022. The Greens do not run the government, and in most years they do not run the opposition either — but for a large share of contested legislation, nothing passes the Senate without their vote or someone else's. That position, a crossbench party whose support is genuinely uncertain and genuinely necessary, is what politics calls holding the balance of power: not a fringe role, but close to the most consequential seat at the table, because a government that cannot get bills through the Senate cannot govern beyond announcing intentions. This topic traces how the Greens have used that position — on housing funding, on rent policy, on negative gearing and capital gains tax, and on new coal and gas approvals — and asks what the leverage has actually delivered, and at what cost, for renters like Renee.
What the Greens did with the balance of power
Since the 2022 election, the Greens have held the second-largest bloc in the federal Senate: twelve senators, behind only the two major parties (Australian Electoral Commission, 2022 federal election, Senate results). Because neither Labor nor the Coalition controls a Senate majority alone, and because Labor and the Greens combined still fall one vote short of the thirty-nine needed to pass a bill without support from elsewhere (approx.) (AEC, 2022 Senate results), almost every contested government bill needs either the Coalition's votes or the votes of the Greens plus at least one more crossbencher — Tasmanian senator Jacqui Lambie's party or ACT independent David Pocock, among others. On housing and climate legislation, where the Coalition has often opposed the government from the right, that has left the Greens as the crossbench bloc Labor most often has to negotiate with from the left: support in exchange for amendments, not automatic backing for the government's first draft.
The clearest test of that leverage was the Housing Australia Future Fund, introduced to Parliament in February 2023 as the centrepiece of the government's social-housing agenda: a permanent $10 billion investment fund whose earnings, not its capital, would pay for new social and affordable homes, targeting around 30,000 homes over five years, including several thousand for women and children escaping domestic violence and older women at risk of homelessness (approx.) (Housing Australia Future Fund Act 2023; Parliament of Australia, Bills Digest, Housing Australia Future Fund Bill 2023). The Greens, joined by the Coalition on the relevant procedural votes, twice declined to let the bill pass the Senate in the first half of 2023. Their argument: a fund whose annual payout depends on investment returns could deliver little or nothing in a weak year for markets, and any new housing fund should come with a national freeze on rent increases attached. The government did not concede the rent freeze. It did concede a funding floor. From September 2023, when the bill finally passed, the fund carried a guaranteed minimum of $500 million a year for housing regardless of investment performance (approx.) (Housing Australia Future Fund Act 2023), and the government separately committed a further $2 billion directly to the states for social housing through a new Social Housing Accelerator payment, announced in the same mid-2023 window the Senate stand-off was under way (Commonwealth Budget-related announcements, 2023). The bill received royal assent in September 2023, roughly seven months after it was first introduced (approx.) (Parliament of Australia, Bills Digest, Housing Australia Future Fund Bill 2023).
The rent freeze the Greens wanted attached to the HAFF did not disappear once the bill passed; it simply moved to a different forum. Through 2023 the party pushed federal and state governments to adopt a national freeze, or failing that a cap, on rent increases, tying any rise to inflation and limiting how often a landlord could raise the rent. National Cabinet — the forum of the Prime Minister and the state and territory leaders — considered the idea in August 2023 and rejected both a freeze and a nationally mandated cap, agreeing instead to a narrower package of "nationally consistent" renters' rights, including limiting rent increases to once a year, with the detail left to the states to implement (National Cabinet communique, Aug-2023). The Greens called the outcome inadequate and kept pressing the demand, making a rent freeze or cap a condition of their support for the government's subsequent Help to Buy shared-equity legislation, which they also held up in the Senate through late 2023 and into 2024 before eventually letting it pass (approx.) (Parliament of Australia, Bills Digest, Help to Buy Bill 2023).
On climate, the Greens' leverage produced a different kind of outcome — a change secured before a bill's final vote, rather than a change forced onto a bill already before the Senate. In late 2022 and early 2023, then Greens leader Adam Bandt made the party's support for the government's Safeguard Mechanism reforms — the scheme requiring Australia's roughly two hundred largest industrial emitters to progressively cut emissions or buy carbon credits — conditional on a ban on new coal and gas projects. The government refused an outright moratorium, arguing it would unwind investment approvals and contracts already under way. After weeks of negotiation with Climate Change and Energy Minister Chris Bowen, the Greens dropped the moratorium demand in exchange for a different concession: a legislated absolute ceiling, or "hard cap," on the total emissions the safeguard facilities can produce on top of the scheme's existing facility-by-facility decline rate, plus tighter limits on how new gas projects could rely on offsets (approx.) (Safeguard Mechanism (Crediting) Amendment Act 2023; Parliament of Australia, Bills Digest, Safeguard Mechanism (Crediting) Amendment Bill 2023). The amended bill passed the Senate in March 2023 with Greens support (approx.) (Parliament of Australia, Bills Digest, Safeguard Mechanism (Crediting) Amendment Bill 2023) — a genuine legislative win for the Greens' bargaining position, even without the outright ban the party had originally sought.
Two further Greens policies have not, as at the time of writing, been enacted — but they sit permanently on the table as the price of future cooperation. The party's platform calls for phasing out negative gearing, the tax rule that lets property investors offset a rental property's losses against their other income, for investors who own more than one property, while grandfathering existing arrangements, and for cutting and then abolishing the 50 per cent discount investors receive on capital gains tax when they sell an investment property (Australian Greens, housing policy platform). It is not an idea without precedent: the Labor Party itself took a narrower version — limiting negative gearing to new-build properties only, and halving the CGT discount — to the 2019 election, before abandoning it after that election loss (ALP, 2019 election platform; Parliamentary Budget Office, 2019 policy costings). The Greens' current version goes further than the policy Labor once proposed and has since dropped, and the party has signalled repeatedly that it would be a live bargaining chip in any future negotiation over housing or tax legislation where its vote is decisive.
This is not the first Parliament in which the Greens have held this kind of leverage, and the earlier episode is worth setting out because it is the party's strongest precedent. Between 2010 and 2013, under the minority Gillard government, the Greens' single House of Representatives seat — held first by then-leader Bob Brown and later by Adam Bandt — combined with a handful of independents to hold the balance of power in the House itself, not just the Senate. A formal agreement between Labor and the Greens, signed in September 2010, delivered Greens support for confidence and supply in exchange for a seat on a Multi-Party Climate Change Committee that went on to design Australia's first, and to date only, economy-wide carbon price, legislated through the Clean Energy Act 2011 (Parliament of Australia, Greens–Labor Agreement, Sep-2010; Clean Energy Act 2011). That episode is the clearest historical precedent for the argument the Greens make today: that a Parliament where their vote is decisive does not just slow legislation down. It can also make legislation more ambitious than a majority government would have chosen on its own.
The strongest case for the policy
Put the Greens' defence at its best
The Greens argue, consistently and not unreasonably, that they use the leverage the Senate gives them to push a timid government toward more ambitious action on exactly the crises this site documents elsewhere: a housing system that has left rents and prices at multi-decade highs relative to income, and a climate transition that keeps slipping behind the pace scientists say is required. On their account, minority influence is not obstruction for its own sake; it is the only lever available to a party that will not, on current polling, form government outright, and a Westminster system without a Senate majority is built on the premise that a government has to persuade, not simply legislate. The historical case is real: the 2010–13 Multi-Party Climate Change Committee, which the Greens' balance-of-power position made possible, produced Australia's only national carbon price, a policy many economists still regard as one of the more efficient climate instruments the country has ever legislated (Grattan Institute, secondary commentary). On housing, the Greens can point to a concrete, verifiable outcome from the 2023 stand-off: the government's original Housing Australia Future Fund design would have let disbursements fall toward zero in a poor investment year, and the guaranteed $500 million floor that now exists, exists because the Greens withheld their vote until it was added. On climate, the hard cap written into the Safeguard Mechanism is a genuine tightening of the scheme beyond what the government first proposed, and it exists for the same reason. The Greens' answer to the charge that they cause delay is that delay is the price of improvement, not a design flaw: a bill passed seven months later but carrying a funding guarantee it did not previously have is, on their account, a better bill — and a Parliament that rubber-stamps a government's first draft without argument is not obviously healthier than one that fights over it in public, on the record, in front of the country it governs.
The evidence: what leverage bought, in numbers
The arithmetic behind the leverage
The mechanics matter, because they explain why the Greens' influence has been concentrated so heavily on housing and climate rather than spread evenly across the whole legislative program. A minor party holding twelve of seventy-six Senate seats cannot force anything through on its own; it can only ever withhold a vote the government needs. Where the Coalition already opposes a bill, as it has on most of the government's housing and climate agenda, the Greens' twelve votes plus Labor's twenty-six become the government's most direct path to a majority, one vote short, and that single missing vote is what gives the Greens genuine bargaining power rather than symbolic protest power. Where the Coalition supports a bill instead — as it more often has on national-security, industrial-relations or law-and-order legislation — the Greens' votes are simply not needed, and their leverage evaporates. The pattern of where the Greens have actually extracted concessions, concentrated in housing funding and climate design rather than spread across government business generally, is exactly what that arithmetic predicts.
The Housing Australia Future Fund: a year of leverage
The HAFF stand-off is worth laying out on a timeline, because the duration of the delay is itself part of the evidence. The bill was introduced in February 2023. It was blocked on procedural Senate votes by the Greens and the Coalition acting together — an unusual left–right combination — first around the middle of 2023 and again the following month, each time on the Greens' objection that the fund's design left annual disbursements dependent on investment markets rather than guaranteed. The government held its position through the northern winter of the parliamentary calendar before moving in August and September 2023, adding the $500 million guaranteed floor and the separate $2 billion Social Housing Accelerator payment to the states. The bill passed the Senate in September 2023, receiving royal assent that month — around seven months, and two blocked votes, after it was first introduced (approx.) (Parliament of Australia, Bills Digest, Housing Australia Future Fund Bill 2023; Housing Australia Future Fund Act 2023).
Every month of that stand-off was a month in which the fund's promised homes were not yet being commissioned, and a month in which people in Renee's position had no clearer answer about when a place might open up. That cost is real, even if it is hard to put a precise dollar figure on it, and it sits on the other side of the ledger from the funding floor the delay ultimately bought.
What the Greens sought, and what they actually secured
Set the four major demands next to their outcomes and a genuinely mixed record appears — not the clean story either the Greens' critics or the Greens' own communications tend to tell.
Two of the four demands mapped in this topic — the HAFF funding floor and the Safeguard Mechanism's hard cap — were substantially won. Two of the largest and most economically consequential demands — a national rent freeze or cap, and an outright ban on new coal and gas approvals — were not, at least not federally and not yet. What the Greens secured instead, in both cases, was a harder-edged version of a policy the government had already decided to pursue: a guarantee inside a fund Labor was always going to legislate, a ceiling inside a mechanism Labor was always going to reform. That is a meaningfully different achievement from reshaping government policy from the ground up, and it is worth stating plainly, because it cuts against the simplest version of both the Greens' own account of their influence and their critics' account of Greens obstruction. The party has moved the government's bills toward the margin of what it wanted. It has not, so far, forced the government to adopt its central economic proposals outright.
Negative gearing and the capital gains tax discount: the demand that keeps returning
The reason those two undelivered demands matter for the future, rather than only the record so far, is that neither has left the table. The Greens have reaffirmed the negative-gearing and CGT-discount policy at successive elections, and senior figures in the party have said publicly that any future Parliament in which their vote is decisive — a second minority government, or a Senate arithmetic even tighter than 2022's — would see the policy raised again as a condition of cooperation on housing or tax legislation. The scale of the change under discussion is not small. Negative gearing and the CGT discount are two of the largest concessions in the federal tax system connected to housing, and removing or sharply narrowing them for investors with more than one property would represent one of the biggest shifts in property-investor tax treatment since the CGT discount itself was introduced in 1999 (Australian Taxation Office, historical CGT provisions). The Parliamentary Budget Office's 2019 costing of Labor's narrower version — new-build-only negative gearing plus a halved CGT discount — found it would raise government revenue by billions of dollars over the medium term (approx.) (Parliamentary Budget Office, 2019 policy costings), which is one reason the idea keeps recurring in tax-reform debates even after Labor itself dropped it. The Greens' version goes further, and its revenue and market effects have not been separately, publicly costed by the PBO at the scale the party now proposes.
A guaranteed floor added to a housing fund, and a hard cap added to a pollution scheme, are real wins the Greens can point to. An outright ban on new coal and gas, and a national freeze on rent increases, are not — not yet.
The critique: leverage without the load-bearing responsibility
The first problem with this pattern is the one Renee Fitzgerald's four-year wait already illustrates: delay has a real cost that does not show up in any Hansard record. Every month the HAFF sat blocked in the Senate was a month in which construction on the fund's promised homes could not begin, and a month in which the people on state waiting lists — more than 175,000 households nationally at any given time across the decade (approx.) (state and territory housing department data, various years) — had one fewer month of housing supply moving toward them. A negotiation that improves a bill's design is not free even when it succeeds; the seven months the HAFF spent blocked are seven months this site's companion analysis of the HAFF and the supply-side gap shows the fund could not have been building toward its 30,000-home target, on top of the fund's own structural limits as a demand-side and supply-adjacent instrument rather than a construction program in its own right.
The second problem is what the concessions themselves added to the budget's structure. The $500 million guaranteed floor and the $2 billion Social Housing Accelerator did not appear from nowhere; they are additional Commonwealth commitments layered onto a fund that was already, by design, off-budget — its $10 billion capital sits outside the underlying cash balance the government reports as its headline fiscal position, as this site's analysis of off-budget funds and the accounting question sets out in detail. A Senate negotiation that produces bigger guarantees is, from a housing perspective, an improvement. From a fiscal-transparency perspective, it is one more instance of a growing pattern: major spending commitments secured or expanded through Senate negotiation, sitting outside the ordinary budget process that would otherwise force them to compete against health, education and defence funding for scrutiny in the same document, in the same year.
The third problem is the one the two undelivered demands point toward, because they describe the next round of leverage rather than the last one. A binding national rent freeze or cap remains Greens policy, and the party continues to press it in state-level tenancy debates even where it has not succeeded federally. The economic literature on rent control is unusually settled for a contested policy area: this site's companion analysis of rent freezes, negative gearing and the economics of the Greens' housing plan sets out in detail the near-consensus finding, across decades of empirical studies in the United States, Europe and Australia, that binding rent controls reduce the supply and quality of rental housing over time by making new investment in rental property less attractive relative to its expected return (AHURI; Grattan Institute; Productivity Commission, secondary sources). A freeze or cap imposed into a market already short of homes, at the exact moment the Housing Accord is trying to attract more institutional and private capital into build-to-rent and new supply, risks working directly against the fund the Greens themselves fought to strengthen.
The negative-gearing and CGT-discount proposal carries a version of the same risk, at a different point in the market. The large majority of Australia's rental homes are supplied by private investors rather than by government or community housing providers (Australian Bureau of Statistics, Census of Population and Housing, tenure and landlord type), which means investor behaviour, not just construction rates, sets the effective supply of rental stock in the short run. Phasing out negative gearing and abolishing the CGT discount for multi-property investors, especially without careful grandfathering and staging, risks prompting exactly the kind of investor pull-back landlords' groups warned about when Labor floated a milder version in 2019 — a risk this site examines in full in the companion topic on the economics of the Greens' housing plan. Fewer investors holding existing rental properties does not automatically mean more homes for owner-occupiers; a sold investment property is typically bought by another investor or an owner-occupier who was renting somewhere else, and the net effect on the total number of homes available to rent, versus the total number of homes available to buy, depends on the pace and scale of the change far more than on its direction.
The coal-and-gas moratorium demand carries the clearest investment-chilling risk of the four, because energy investment decisions are made years in advance and are unusually sensitive to political and regulatory uncertainty. Even though the Greens did not secure an outright ban, the fact that a major crossbench party held it as a live negotiating demand for months in 2022–23 is itself a signal to investors weighing new gas projects — the same investors whose supply decisions this site's analysis of gas, energy security and the interventions shows AEMO and the ACCC have repeatedly flagged as critical to keeping the east-coast grid reliable through the 2020s. A future Parliament in which the Greens hold enough leverage to convert that demand from a bargaining chip into an enacted condition would be legislating directly against the gas supply the market operator says the grid still needs as a firming fuel while renewable and transmission build-out catches up to its own targets.
Underneath all four cases sits a structural asymmetry worth naming plainly. A governing party has to reconcile every demand against every other commitment in the same budget, the same construction sector and the same investment climate, because it will be judged on the whole outcome. A crossbench party holding the balance of power does not face that same reconciliation. It can hold out for the most ambitious version of a single policy without having to weigh that policy's effect on the dozens of other things a government is simultaneously trying to fund and build, and without ever having to assemble the full parliamentary majority a change of that scale would require to become law on its own. That asymmetry is not evidence of bad faith — the Greens are using the position the electorate gave them, exactly as the rules allow. But it does mean the leverage this topic documents has, so far, been tested only at the margins of government bills the Greens did not design. The forward risk is what happens if that same instinct is applied with more leverage, or less compromise, to a policy program the Greens would prefer to enact in full.
What the Greens got right — and the limits of the critique
A fair audit has to credit what this record actually shows, not the caricature of either side. First, the 2010–13 carbon-price episode is a genuine and significant policy achievement, not a footnote. The Clean Energy Act 2011, designed through the Multi-Party Climate Change Committee the Greens' balance-of-power position made possible, put a price on carbon across most of the economy for the first time, and emissions from the electricity sector fell measurably while it was in place before its repeal in 2014 under the following government (Clean Energy Regulator, historical emissions data; Parliament of Australia, Clean Energy Act 2011). Whatever view is taken of the policy's later repeal, the fact that it existed at all, in a Westminster system that rarely produces bold single-sector reform without a governing majority behind it, supports the Greens' broader argument that minority leverage can raise a government's ambition rather than only obstruct it.
Second, the two concessions won in this Parliament are real and measurable, not symbolic. The $500 million guaranteed floor removes a genuine design flaw from the HAFF — a fund whose social-housing output could otherwise have fallen toward zero in a run of weak investment years is a worse fund than one with a guaranteed minimum, on any reasonable reading, and renters and community-housing providers are better off with the floor than without it. The Safeguard Mechanism's hard cap is a comparable improvement on the emissions side: a facility-by-facility decline rate alone cannot guarantee a sector-wide ceiling if the number of covered facilities grows, and the cap closes that gap. Both changes exist because the Greens withheld their vote until they were added, and both are more defensible, evidence-based improvements than the party's harshest critics tend to acknowledge.
Third, it is fair to note that the Greens did not simply hold every bill hostage indefinitely. In both the HAFF and Safeguard Mechanism negotiations, the party ultimately accepted a negotiated outcome that fell short of its original, maximalist demand — a guaranteed floor rather than the rent freeze it wanted attached to housing funding, a hard cap rather than the outright ban it wanted on new coal and gas. That is a pattern of eventual compromise, not pure obstruction, and it complicates any account of the Greens as simply blocking government business without limit. The party's own account — that it uses leverage to improve bills rather than to prevent government from functioning at all — is at least partly borne out by what actually happened to these two pieces of legislation.
Fourth, the underlying pressure the Greens are responding to on housing is real and long-running, and it did not begin with this Parliament. This site's analysis of the housing affordability emergency traces price-to-income ratios and deposit hurdles that have been worsening for well over a decade, under governments of both major parties. A party arguing that a decade of price signals alone has failed to deliver enough supply or enough affordability is not inventing a crisis to justify its leverage; it is responding to one that predates its current Senate numbers and that this site's own analysis independently documents as severe. The disagreement worth having is over which remedy actually helps — not over whether renters and first-home buyers are under genuine, well-evidenced pressure.
The same leverage that turned a market-dependent housing fund into one with a guaranteed floor could, in a tighter future Parliament, turn a rent-freeze proposal into an enacted rent cap — with consequences renters would live with for years, not months.
The risk to the future
Leverage tested at the margins today could be applied to the core tomorrow
The Senate arithmetic that has given the Greens their post-2022 leverage did not disappear at the 2025 election, and on the balance of the evidence it changed only at the edges: the Greens' House of Representatives numbers fell sharply, including the loss of their own leader's seat (approx.), but their Senate position — the seat of their real leverage over legislation — was far less affected (Australian Electoral Commission, 2025 federal election results). That means the same mechanism this topic documents is still live for the next Parliament, and possibly for several after it. So far, that leverage has been tested only against bills the government itself designed and was already committed to passing in some form — a housing fund, a reformed pollution-pricing mechanism — and the concessions extracted, a funding floor and an emissions cap, have tightened rather than redesigned those bills. The undelivered demands are a different order of risk. A binding national rent freeze or cap, if it were ever enacted at scale rather than merely proposed, would arrive in a rental market this site's own analysis shows is already critically short of supply, and the empirical literature on rent control is unusually consistent that price ceilings of this kind reduce investment in new and existing rental stock over time — the opposite of what a housing-short country needs. A sudden, poorly staged withdrawal of negative gearing and the CGT discount for multi-property investors risks a similar dynamic on the ownership side: less certainty for the investors who currently supply most of the country's rental homes, at a moment the market can least afford an abrupt pull-back. And a hardening of the coal-and-gas moratorium demand into an enacted condition would chill exactly the gas investment the market operator has repeatedly warned the grid still needs while renewable capacity and transmission catch up to their own targets. None of this is inevitable — each of these remains a proposal, not a law, and the same party has shown it will compromise rather than hold out indefinitely. But the mechanism that produced the HAFF floor and the Safeguard cap is the same mechanism that could, in a future Parliament with a marginally different number on a marginally different bill, produce something much larger and much harder to reverse. Whether that leverage keeps sharpening the government's ambition, as it did on housing funding and the pollution cap, or is used to force through an economic program that deepens the very supply-side crises this site documents, will do more to shape the next decade of Australian housing and energy policy than almost any single decision either major party makes on its own.