Suspended Umno deputy president Muhyiddin Yassin's call for institutional reforms has sparked renewed interest for cooperation between rebels in the ruling party and the opposition.

Both Pakatan Harapan chief secretary Saifuddin Abdullah and PKR vice-president Rafizi Ramli were confident this will be discussed in the next Harapan presidential council meeting, to be held during the first week of Parliament which begins on March 7.

"We have not discussed (working with Umno rebels), but the latest developments definitely warrant a closer look.

"I will propose that a secretariat council meeting be convened this week to discuss all these latest issues and we will make a preliminary report to our respective parties for deliberation at the presidential council meeting," Rafizi told Malaysiakini today.

Previously, Rafizi and other opposition leaders had expressed reservations at working with Umno dissenters such as Muhyiddin and former premier Dr Mahathir Mohamad.

This was because at the time, they were only focused on removing Prime Minister Najib Abdul Razak, but had no interest in institutional reforms.

However, Muhyiddin changed his tune yesterday after he was suspended as Umno number two, and pledged to stand with the rakyat against "tyranny".

This move for reform, Saifuddin said, would be the basis of terms of cooperation between the two sides.

"If there's any negotiations with them (Umno rebels), the institituional overhaul must be taken into consideration," he said.

Meanwhile, Parti Amanah Negara (Amanah) secretary-general Mohd Anuar Tahir added that as long as they - or any other party - were going to be steadfast in fighting for change, then the opposition would be willing to work with them.

Rafizi echoed similar sentiments, adding that it was important to bring together all groups to "put a stop to Najib's rule".

Rafizi said former de facto law minister Zaid Ibrahim's March 27 anti-Najib gathering would be a good platform for such talks on cooperation.

"It will give the message to the public that we are willing to set aside differences to focus on taking on Najib together, especially since there is an acknowledgement of sorts from the Umno dissenters of the need for urgent reforms.

"That message is important to give some sense of hope to the public," he added.