The ACT Greens will sit on the crossbench in the Legislative Assembly, after talks with ACT Labor failed to reach an agreement on the minor party's role in government.
Labor's Andrew Barr will have the Greens' support to remain as chief minister and Labor will enter minority government. However, Mr Barr will no longer have his longest-serving cabinet colleague to draw on when he appoints ministers later this week.
Greens leader Shane Rattenbury said he had written to Mr Barr late on Tuesday night, offering confidence and supply for the government, and support for the Labor leader to remain as chief minister, in exchange for Labor's backing on several key Greens policies.
"By sitting on the crossbench during this term of government, we are confident we are using the best mechanism available to us to push for bolder change and create a better deal for Canberrans - to build public housing, go further, faster on our nation-leading climate action and truly protect and restore our environment," Mr Rattenbury said.
A Labor spokeswoman said the ALP had offered the Greens positions in cabinet but would respect their decision to sit on the crossbench and would look forward to ongoing discussions to deliver good government.
"We have many areas of policy agreement and during these negotiations we have reached agreement on a large number of priority reforms for the coming parliamentary term," the spokeswoman said.
"As a result of these discussions, the ACT Greens have indicated that they will support Andrew Barr as the chief minister and have guaranteed supply to the government. This will enable the formation of a minority ACT Labor government."
Mr Rattenbury, who had been a minister since 2012, said the text of an agreement between Labor and the Greens would be released shortly and the details of the policies Labor committed to supporting would be released in the coming days.
"Unfortunately over the past two weeks, negotiations with ACT Labor have not delivered enough of a commitment to address these big issues in order to give us confidence that any power-sharing agreement would deliver the level of change that Canberra needs," he said.
Mr Rattenbury said Labor had been unwilling to commit to extra public housing beyond its own policy, accelerate construction timelines for light rail or provide specific funding to boost environmental protection and restoration.
"The ACT Greens did not demand an exact commitment to our policies - negotiation requires compromise and we offered compromise. But on some of the most important matters to our party, Labor was unwilling to budge," he said.
Mr Rattenbury, who would have been the second longest-serving cabinet minister after Mr Barr, said the Greens had always put people before power, and would champion key issues from the crossbench, where the party would be a "constructive, collaborative and progressive alternative to Labor".
A Labor spokeswoman said the negotiations had been conducted in good faith and with mutual respect, and both sides acknowledged that working together in government would not come at any cost.
"During the negotiations, the ACT Greens indicated publicly that they were open to a different approach to their engagement in the 11th Legislative Assembly. Labor said from the outset that we would respect the Green's internal process and allow it to reach a conclusion," the spokeswoman said.
Mr Barr is expected to unveil his new cabinet later this week. It will be the first time Mr Barr assembles a ministry without Mr Rattenbury.
Extensive talks between Labor and the Greens had continued on Tuesday, as the Greens publicly remained coy about whether they were seeking to enter cabinet or would prefer to sit on the crossbench.
A spokeswoman for Chief Minister Andrew Barr had said the discussions would conclude ahead of the ceremonial sitting. The sitting will begin at 9.30am on Wednesday.
"Extensive and detailed negotiations have taken place between ACT Labor and the ACT Greens over the past two weeks," the spokeswoman said before 5pm.
"The process is nearing finalisation. The goal of these negotiations is to deliver progressive and stable government that can deliver for Canberra over the next four years."
Mr Barr has remained largely silent through the negotiating process, making no public comments on the talks since he said the Greens could not expect to be a "minister for good news".
Mr Barr is expected to be voted in again as chief minister on Wednesday when the Legislative Assembly holds a ballot for the position.
The ballot is unique among Australian parliaments. The ballot will take place after a speaker is elected and before any other business.
The speaker and deputy speaker are expected to come from the crossbench and opposition.
Mr Rattenbury on Friday told his party's members the Greens would not enter into a coalition with Labor if the major party's plans for Canberra could not be amended because the ACT "did not vote for business as usual".
The Greens were using the negotiations to let Labor know the Greens had "big new ideas, the experience to implement them, and a huge amount of determination to change life in Canberra for the better", Mr Rattenbury said.
Mr Rattenbury went on: "Minority government requires compromise. As many of you know from our member survey and consultation meeting last weekend, the Greens are looking at every option, from sitting on the crossbench with no formal agreement on confidence or supply, through to a governing partnership with Greens as part of cabinet."
Labor holds 10 seats in the Legislative Assembly after the election, while the ACT Greens lost two seats and now hold four. With 13 seats needed for a majority, the two parties can govern together.
The split means the Liberals could not form a government with the support of two independents. Opposition Leader Leanne Castley has effectively ruled out working with the Greens to form government, citing Elizabeth Lee's talks with the Greens as a reason for withdrawing support for her predecessor.
In 2020, Labor and the Greens revealed their parliamentary and governing agreement on Monday, November 2, ahead of the first sitting of the 10th Legislative Assembly on Tuesday, November 3.
The deal afforded the Greens three spots in cabinet after the party won six seats, the party's best result in the Assembly. Mr Rattenbury was the only Greens minister to hold onto his seat at the 2024 election, a result which has exposed some rifts in the party over its direction.
