PKR has agreed with Pakatan Harapan's suggestion to name Dr Mahathir Mohamad as their nominee for the premiership along with Dr Wan Azizah Wan Ismail as deputy premier.

According to sources, this was decided during a political bureau meeting on Dec 19 and the proposal had the endorsement of PKR de facto leader Anwar Ibrahim.

Many PKR leaders were tight-lipped about this as a gag order has been issued.

The Dr M-Wan Azizah combination was proposed during the Harapan leadership retreat earlier this month.

When news of this proposal was leaked, some of the PKR grassroots were unhappy because they believe Mahathir's 22-year rule had contributed to Anwar's jailing in 1999.

The prospect of having Mahathir back at the helm has been deemed too much to bear for some.

Anwar's supporters formed Parti Keadilan Nasional - PKR's predecessor - following his sacking as deputy prime minister and subsequent sodomy trial.

Anwar subsequently was convicted of sodomy again and has been serving a jail term since 2014.

According to sources, PKR's politburo had agreed to endorse the Dr M-Wan Azizah combination on condition that Mahathir agrees to pursue Anwar's release from prison and hand over power to him.

"We also want (Mahathir) to promise that he will only be an interim prime minister until Anwar can take over," said the source.

Another source said PKR secretary-general Saifuddin Nasution (photo) has been tasked with securing similar commitments from Harapan's three other component parties - Bersatu, DAP and Amanah.

The source said the party could only reveal further details or formally endorse the Dr M-Wan Azizah combination should the other parties agree to these conditions.

It is uncertain if there has been any progress with Saifuddin's task, although sources confirmed that he visited DAP parliamentary leader Lim Kit Siang, who is recovering from a surgery, today.

Mahathir, 92, has repeatedly stated that he was not keen on running for office again.

But if this was a necessity, he said he would prefer to be fielded in Langkawi or Putrajaya - both cities which he helped build.

Anwar is expected to be released from prison in June next year but he has to get a pardon from the king and win a parliamentary seat before he can take over the prime minister's post should Harapan win the upcoming general election.