Dr Mahathir Mohamad says his four-member bloc will not support the 2021 budget in a crucial vote by MPs tomorrow.
The former prime minister called for the budget, tabled on Nov 6, to be amended or for a new budget to be tabled.
Writing in his blog, Mahathir also accused the Perikatan Nasional government of trying to ensure that it remains in power.
“What seems to be a priority for the government is to ensure that the budget, which does not take into account the people’s interest but its political continuity, is passed as soon as possible,” he said.
If the budget fails to be passed tomorrow, he said, a new government can make amendments or table a new budget through a special parliamentary session.
He said any defeat of the budget would mean that the government has lost its legitimacy, adding that the prime minister would resign if he was “someone with dignity”.
Mahathir also said the unusual times of the Covid-19 crisis mean that a snap poll is not an option in the event that the government collapses.
He proposed that the Yang di-Pertuan Agong appoint an MP who has the majority support in the Dewan Rakyat to form the government.
“This will ensure that the new government has legitimacy which will not be questioned, as is the case with the current backdoor government,” he added.
Muhyiddin Yassin was sworn in to power following a series of audiences granted by Sultan Abdullah Sultan Ahmad Shah to the 222 MPs, to find out who they support as prime minister.
But opposition MPs have disputed Muhyiddin’s numbers and have repeatedly attempted to push a motion of no confidence in the Dewan Rakyat.
The nearest such vote in the Dewan Rakyat was held over a government motion to replace the Dewan Rakyat speaker, which the ruling bloc won by a two-vote majority.
In October, PKR president Anwar Ibrahim announced that he had the majority support, but failed to show details of his claim during an audience with Sultan Abdullah.
The Agong subsequently reminded politicians not to indulge in “politicking”, with several other statements from the palace urging MPs to show unity during the time of the pandemic by supporting the 2021 budget.
The palace had earlier refused to declare an emergency amid fears that a collapse of the government during the budget vote could lead to pandemic-season elections, which health authorities have warned against.