KUALA LUMPUR - Prime Minister Mahathir Mohamad says he will stick with an agreed plan to pass the prime ministership to MP Anwar Ibrahim, amid ongoing mudslinging in Malaysian politics caused by the release last month of a gay-sex video.

Datuk Seri Anwar, president of Parti Keadilan Rakyat (PKR), and his deputy Azmin Ali, along with their supporters, have been attacking one another daily following the release of the video clip that purportedly showed Datuk Seri Azmin engaged in sex acts with a young man.

Both Mr Anwar, 71, and Mr Azmin, 54, have been touted as prospective prime ministers by their factions in PKR, the biggest party in the ruling Pakatan Harapan (PH) government.

Tun Dr Mahathir told Turkish television channel TRT that he won't renege on a PH plan to make Mr Anwar the next prime minister.

Dr Mahathir, asked to comment on his ties with Mr Anwar, who was his protege turned enemy, and now turned ally again, said: "Well, I have already agreed that when I step down, he will take over from me as prime minister."

"That is a promise I made and I will stay with the promise," the 94-year-old added.

Dr Mahathir has variously said he would step down between two and three years after becoming prime minister, following PH's surprise electoral victory in the general election in May last year.

But he has not given a specific date on when he would do so, which raised some suspicion in the Anwar camp that Dr Mahathir would likely appoint Mr Azmin as Malaysia's eighth prime minister.

But Dr Mahathir told TRT on the succession plan: "I'm not going against my own promise. Whatever happens, I will stick to the promise I made."

Mr Azmin has said in recent days that he agreed with opposition Parti Islam SeMalaysia and some leaders in Umno, another large Malay Muslim opposition party, that Dr Mahathir should serve as prime minister for the full five-year term.