Australia's conservative Liberal-National coalition - the nation's main opposition political party - has split after a partnership lasting almost 80 years.
The move marks a seismic change in the country's political landscape and comes just weeks after a federal election that saw Labor win a second term in a landslide victory.
Nationals leader David Littleproud on Tuesday said his party was not re-entering a coalition agreement, amid policy disagreements with the Liberal Party as it goes on a journey of "rediscovery" following the emphatic loss.
Littleproud added that the Coalition has been broken and repaired before, and he hoped that - with time - the parties could reconcile again.
"Whilst we have enormous respect for David Littleproud and his team, it is disappointing that the National Party has taken the decision to leave the Coalition," newly elected Liberal leader Sussan Ley said, hours after the shock announcement.
Ley said the founding principle of the Coalition had long been "shared values", but said the Nationals had refused to sign a deal without commitments to "specific policies".
The split comes after days of post-election talks between the two parties about their future, with Littleproud's party - which mainly represents regional communities and often leans more conservative than the Liberals - failing to reach an agreement with their long-time political ally.
A key issue that had strained their relationship was climate and energy, with some in the National Party still opposed to net-zero emissions goals, and wedded to a nuclear power proposal which proved controversial at the election.
Littleproud also pointed to regional infrastructure spending and policies to improve supermarket competition as points of conflict.
Describing it as "one of the hardest political decisions of his life", Littleproud said he had a "respectful conversation" with Ley to inform her of the split on Tuesday morning.
"What this is about is taking a deep breath and saying to the Australian people, this is time apart [for] us to be better, [to] focus on them.
"I gave [Ley] the commitment that I'll work with her every day to help to try to rebuild the relationship to the point we can re-enter a coalition before the next election."
However, he said the National Party would contest the next election solo if unity could not be achieved.
The Liberal-National partnership, which in its current form dates back to the 1940s, has broken down and been re-established several times over the decades. The last time the Coalition split was almost four decades ago, in 1987.
All except one of the 15 electorates the Liberal-National coalition lost at the election were ceded by the Liberals, who saw big swings against them right around the nation.
Support for the Liberals nosedived in more moderate areas, particularly in cities, which analysts largely put down to then-leader Peter Dutton's polarising persona and some Trump-like policies. Ley, his successor, has vowed to bring the party back to the centre-right.
