Interim Prime Minister Dr Mahathir Mohamad and Pakatan Harapan are now working together again based on a mutual agreement that they must prevent corrupt individuals from returning to power, said several sources.

The breakthrough came following discussions between Mahathir and PKR president Anwar Ibrahim at the former's residence in Seri Kembangan last night.

"Both agreed that corrupt Umno leaders must not be allowed to return to rule the country again.

"(Working together) is their only available option, if not the people will suffer," said a source, who was familiar with what was discussed.

The hastily arranged meeting between the duo came after Umno, PAS, MCA and MIC voiced support for Muhyiddin Yassin to become prime minister.

As of last night, Muhyiddin appeared to have, at least on paper, control of the biggest bloc in Parliament, albeit without an outright majority.

This had led to concerns that the many criminal trials against Umno leaders would be stopped if they were allowed to come back to power.

After the meeting with Anwar last night, Mahathir received another group of Harapan leaders at his home this morning to discuss further details.

Anwar was not present at the meeting as he had other matters to attend.

According to sources, a preliminary conclusion was that Harapan's original transition plan would be maintained - Anwar will not be part of the cabinet until Mahathir decides to step down, some time after the Asia-Pacific Economic Cooperation (Apec) summit in November.

"There are other conditions set between the two, but this is for the two of them," said a source.

Harapan's original transition plan for Mahathir to hand over reins to Anwar was a sore point for the coalition, culminating in a meeting last Friday where some Harapan leaders demanded a definitive date.

In the end, it was decided that Mahathir could stay on as long as he liked.

However, a group of PKR MPs led by Azmin Ali decided to pull out of the party and trigger a bid to form a government with Umno and PAS to form a government led by Mahathir in what is now known as the "Sheraton Move".

That plan did not materialise as Mahathir refused to cooperate with Umno.