PKR deputy president Azmin Ali said cooperation between Pakatan Harapan, PAS and former prime minister Dr Mahathir Mohamad's new party could form the ultimate coalition to topple BN.

"I welcome all federal opposition parties because our common enemy is Umno-BN.

"We have to unite and work as a team. We must have the same policies and framework," he told reporters at the Selangor State Secretariat Building in Shah Alam today.

"We certainly welcome them into Pakatan Harapan to expand our struggles, if the new party's objectives are in line with ours. We need to be more inclusive and prepare to face the 14th general election," he said.

Mahathir last month said that an opposition coalition would be formed between DAP, PKR, Amanah and his new party, to go up against BN in the 14th general election.

It was reported that former deputy prime minister Muhyiddin Yassin would be the president of the new party.

The Selangor government is a coalition government made up of DAP, PKR and PAS representatives, despite the break-up of the triparite Pakatan Rakyat made up of these parties last year.

On a separate matter, Azmin sidestepped questions on PKR seeking extra seats in Penang.

"I have issued a statement on this matter and the issue of one or two seats does not arise," he said.

This is after Penang Chief Minister Lim Guan Eng said DAP had scrapped its plans to call snap polls in the state, after a consensus could not be reached with PKR.

Lim said PKR had sought to contest an additional two seats if a snap election was called, but DAP could not meet this request.