Embattled Umno president Ahmad Zahid Hamidi has warned Barisan Nasional (BN) MPs that he has the final say in any decision on forming alliances to establish the next government.

This comes after Sarawak's GPS announced that the coalition has agreed to be part of Perikatan Nasional (PN) and BN in order to reach the numbers needed to form the federal government.

Zahid denied that BN had held negotiations with PN to enter into any understanding to form the government.

"All BN MPs who won in GE15 have signed an undertaking to give me the mandate as the president to determine any political coalition in the formation of the government," said Zahid, who is facing intense pressure from Umno leaders to quit following the party's devastating performance at the election yesterday.

Referring to the recently introduced anti-hopping law, Zahid also reminded them that defying party orders would result in them being sacked as well as losing their seats.

There has been a chorus of calls for Zahid to step down as Umno president and chairman of BN, after the coalition was trashed by PN, leaving it with just 30 seats.

Umno information chief Shahril Hamdan and Selangor Umno chief Noh Omar have both quit their posts and urged Zahid to do the same, while MCA slammed his decision to postpone a top-level meeting of BN leaders tonight and warned against the making of any arbitrary decisions.

This afternoon, Sarawak Premier Abang Johari Openg announced that his GPS coalition with 22 seats would back PN chairman Muhyiddin Yassin as prime minister, alongside MPs from Sabah's GRS coalition.

Even in the run-up to the polls, there was intense speculation that Zahid would eventually throw his support behind Pakatan Harapan in the event of a hung parliament, in order to make its chairman Anwar Ibrahim prime minister.

Zahid is a long-time associate of Anwar, from their days in Umno, and both leaders have maintained close ties despite leading rival parties.

Last year, a telephone conversation between them exposed a plot to get Umno to cut ties with Bersatu, just weeks before Zahid and former leader Najib Razak engineered the defection of MPs from Muhyiddin's government, forcing him to resign in August 2021.