The s have formally split with the Liberal party, breaking up the Coalition for the first time since the 1980s due to major policy differences.
The s leader, David Littleproud, said MPs had made the shock decision not to enter into a new coalition agreement with the Liberals in talks at Parliament House on Tuesday, after a breakdown in negotiations with the new opposition leader, Sussan Ley.
Littleproud nominated nuclear policy, a $20bn regional Australia future fund, forced break-up powers in the supermarket sector and minimum standards for communications services in the bush as the key sticking points in the decision.
Sign up for Guardian Australia’s breaking news email
The minor party wanted each policy locked in exchange for a formal agreement with the Liberals, but Ley has promised a wide-ranging policy review with consultation across the party. She ruled out “captain’s calls” after being elected leader.
Ley said the decision was “disappointing”, insisting she wanted to name a joint frontbench and then allow both parties to work on policy development separately. She confirmed the s also demanded shadow ministers have the right to vote against opposition policy in parliament, a move which would be highly unusual.
“As Liberals, we respect their decision and commit to continue working collaboratively with them,” she said in a statement. “The Liberal party’s door remains open to the s’ should they wish to rejoin the coalition before the next election.”
Littleproud gave Ley just half an hour’s warning of the decision to split. Along with senior s, he said the two parties could reunite before the next election, due in 2028, but there was no guarantee.
The split means the parties will not be together in opposition against Labor, which smashed the Coalition in the 3 May election and is on track to have more than 90 seats in the House of Representatives.
The Liberals look set to have 28 lower house seats and the s 15.
s MPs won’t sit in the shadow cabinet and the minor party will make its own policy decisions for the coming term of parliament. The s will field their own roster of spokespeople on key policy portfolios.
“The party will sit alone on a principle basis, on the basis of
looking forward,” Littleproud said.
“It’s on a principle position of making sure that those hard-fought wins are maintained and respected, we continue to look forward.”
It is only the fourth time the Coalition has split formally in the federal political sphere, and the first time since a short breakup over the “Joh for PM” push, which aimed to have the then Queensland premier, Joh Bjelke-Petersen, lead the Liberals and s in Canberra.
The Liberals and s did not enter a coalition after Gough Whitlam’s 1972 election victory, but ran together at the 1974 poll.
Nuclear policy was a major sticking point in Tuesday’s decision. Littleproud said his party remained committed to the introduction of nuclear power in Australia, saying renewable energy had lost its social licence and country communities wanted change.
Littleproud flagged that the two parties could reconnect in the future, saying his door was open to the Liberals.
“We have had a coalition of over 80 years and I suspect we will have one in the future. It has been broken before. What this is about is taking a deep breath and saying to the Australian people, this is time apart [for] us to be better.
“This is a healthy part of our democracy which should be proud of.”
Ley said the Liberals wanted to complete a policy review before locking in positions for the next election.
“As was explained to the s, the Liberal party’s review of election policies was not an indication that any one of them would be abandoned, nor that every single one would be adopted.
“We offered to work constructively with the s, respecting the party’s deeply held views on these issues. We asked the party to work constructively with us, respecting our internal processes. In good faith, the Liberals proposed appointing a joint Coalition shadow ministry now, with separate policy development in each party room and subsequent joint policy positions determined in the usual way.”
Ley said solidarity in the shadow cabinet was non-negotiable and confirmed she would appoint a solely Liberal frontbench in coming days.
The former s leader and deputy prime minister Barnaby Joyce told Guardian Australia it was healthy for the two parties to split for a period of time.
“That election was not good. It was not good for the Liberal party and it was not good for the party,” he said.
Joyce said regional voters had vastly different interests to Australians in the major cities, nominating the infrastructure required for renewable energy projects to connect to the grid.
“It’s not going to be a walk in the park. It is going to come with its complications.”
He said the split was similar to tensions within conservative parties overseas.
“This is not just happening in Australia, this is happening globally. Take [Reform UK leader] Nigel Farage and the Conservative party, or the Maga movement and Donald Trump in the United States. It is a global phenomenon.”
The treasurer, Jim Chalmers, said the Coalition was now “nothing more than a smoking ruin”.
“This is a nuclear meltdown in the Coalition and it’s hard to see how Australians can take them seriously when they don’t even take each other seriously.”
Some Liberals have considered the s a drag on their vote for years. Former Liberal MP Jason Falinski had advocated for a split in the Coalition in recent days, noting the Liberals have been all but wiped out in the major cities and voters were turned off by the party’s views on climate change.