Prime Minister Muhyiddin Yassin's coalition has been roiled by defections of senior figures to a new Malay-based party announced last Friday by Malaysia's former premier Mahathir Mohamad.

The moves threaten to weaken the four-year-old Parti Pribumi Bersatu Malaysia, although it is not even clear if Home Minister Hamzah Zainudin, a Bersatu leader, would allow the new, as yet unnamed, party to be registered.

But that has not stopped three of Bersatu's supreme council members and a Selangor assemblyman from jumping ship, the dissolution of several Bersatu divisions in Selangor and talk of more lawmakers quitting Tan Sri Muhyiddin's party in his own state of Johor.

Mr Ulya Aqamah Husamudin is the third supreme council member to leave Bersatu, following the footsteps of Tun Dr Mahathir's former media adviser, Datuk Kadir Jasin, and Mr Tariq Ismail.

Jeram state assemblyman Mohd Shaid Rosli also quit the party on Saturday, and said that 13 Bersatu branches in Kuala Selangor have been dissolved.

"This will be the first division to be disbanded and I am the first Bersatu state assemblyman in Selangor to leave the party," he said.

There are four other Bersatu assemblymen in Selangor.

Mr Shaid said many party members were unhappy over Bersatu's decision to work with Umno.

"The Bersatu leadership did not discuss the collaboration with its grassroots members. This is unacceptable for us," he added.

Klang Bersatu division chief Syed Abdillah Syed Abdul Aziz also declared the dissolution of the division over the weekend in support of Dr Mahathir's party.

"We... unanimously ask to become members of this new party," Mr Syed Abdillah told a news conference on Saturday.

According to reports, Petaling Jaya Bersatu division chief Mohamad Shafiri Abdul Karim left the party on Saturday night, taking 500 members with him, while 22 committee members of the Bersatu division in Langkawi - Dr Mahathir's seat in Kedah - quit yesterday.

"We left the party based on our principles and honour as to not cave in to the offers of power and kickbacks," deputy division chief Shukor Bahari was quoted as saying by Harian Metro, a Malay daily.

There is also talk of a revolt brewing among Bersatu members in Johor, a claim denied by Johor Bersatu chairman Mazlan Bujang. "Even if there is support (for Dr Mahathir), it would not be more than 5 per cent (of members)," he said.

Dr Mahathir, Malaysia's longest-serving premier, and Mr Muhyiddin founded Bersatu in 2016.

It comprised former Umno leaders who wanted to topple then Prime Minister Najib Razak in the aftermath of the huge scandal surrounding the troubled 1Malaysia Development Berhad state fund.

But the two founding members split up following the February collapse of the Pakatan Harapan (PH) government, after Mr Muhyiddin and other MPs left to form a new alliance that includes Umno and Parti Islam SeMalaysia.

Dr Mahathir, 95, and four other MPs were then kicked out of the party for sitting on the opposition bench in Parliament.

The veteran politician announced the formation of his new party after the Kuala Lumpur High Court allowed an application by Prime Minister Muhyiddin and three others to strike out a suit lodged by Dr Mahathir over the validity of their party membership.

Dr Mahathir has said that the new "independent party" will neither be part of the opposition PH coalition nor the ruling Perikatan Nasional, and indicated that it will contest a by-election in Perak on Aug 29.

Opposition leader and Parti Keadilan Rakyat president Anwar Ibrahim said Malaysia should move away from race-based parties to ensure equality for everyone.

"Some play the bumiputera card to enrich a few families and cronies. We have to put an end to this," he said.