In a statement issued by the palace, King Adbullah said that Muhyiddin, the president of interim prime minister Mahathir Mohamad's Bersatu party, will be sworn in as prime minister on Sunday as he likely commands the most support of any candidate.

Malaysia's constitution stipulates that the king may nominate a prime minister if he deems any candidate "likely to command the confidence of the majority of the MPs," which in practice usually means the leader of the winning side in parliamentary elections.

The announcement came after Mahathir, 94, who resigned on Monday, threw his name into the fray again on Saturday morning.

"I am now confident that I have the numbers needed to garner majority support in the Dewan Rakyat [parliament]," Mahathir said, in a statement released by the Alliance of Hope/Pakatan Harapan (PH).

The 94-year-old Mahathir had led the grouping to a spectacular election win in 2018 but government imploded on Monday when he unexpectedly resigned as prime minister.

Muhyiddin responded later on Saturday by saying he was replacing Mahathir as party chairman, though other party members quickly disputed the attempted takeover as Mahathir surged back into contention to lead the next government.

Muhyiddin had emerged on Friday as front-runner to become prime minister after receiving more backing from lawmakers than Pakatan Harapan's Anwar Ibrahim, a long-time rival and sometime ally of Mahathir.

Citing the "national interest," Anwar on Saturday withdrew his candidacy, and said he had proposed to the country's king "Mahathir Mohamad's name as PM candidate representing PH."

Before the government fell on Monday, Anwar was leader-in-waiting, though Mahathir had sought to postpone the handover.

Saturday's drama comes after a week of deadlock during which Mahathir unsuccessfully pitched a "national unity" government.

As Pakatan Harapan kept insisting it would endorse Anwar for prime minister, Mahathir ruled himself out of the running on Thursday, name-dropping Muhyiddin as an alternative.

However Muhyiddin is counting on the support of the United Malays National Organisation (UMNO), the party of Najib Razak, the former prime minister who is now on trial on charges of looting hundreds of millions of dollars of public money.

Both Mahathir and Pakatan Harapan stated they would not allow UMNO back into government.

Muhyiddin was Najib's deputy before being sacked in 2015 after he criticized his government's response to the corruption allegations.

UMNO endorsed Muhyiddin for prime minister on Friday, after calling earlier in the week for snap elections to resolve the power vacuum created by Mahathir's resignation and the collapse of the government.

Speaking to the media on Saturday, UMNO vice-president Ismail Yassin criticized Mahathir for flip-flopping, saying "at first he wanted [to be prime minister], then he quit, then when Muhyiddin Yassin agreed, he came back, then he agreed that Muhyiddin is the candidate. Now he doesn't agree."

Australian Associated Press