Papua New Guinea's government has been split by the defection of four key ministers to the opposition.
The deputy prime minister, Sir Puka Temu, along with Forest Minister Beldan Namah, Culture Minister Charles Abel and Attorney-General Ano Pala, have publicly announced their move away from the government.
The move sets the stage for Sir Puka to topple current leader Sir Michael Somare.
At a news conference yesterday, Sir Puka said he was leaving because he believed it was the right thing to do.
He also added a vote of no confidence in the government would be moved when parliament sits today.
Transport Minister Don Polye had been expected to launch a leadership challenge at a meeting of the ruling National Alliance Party yesterday.
But Sir Puka's move to the opposition has thrown the political landscape into further uncertainty.