PAS president Abdul Hadi Awang today reiterated that his party will not close its doors to former prime minister Najib Abdul Razak.

Hadi likened that scenario to the Islamist party also accepting Prime Minister Dr Mahathir Mohamad when he was sacked from Umno early in his political career.

"We are open to everyone who can accept us. We even accepted Mahathir in 1969 when he was rejected by Umno," he told a press conference in Marang, Terengganu today.

This was amid calls for Najib to limit his involvement in Umno, due to concerns that his corruption scandals would adversely impact the party.

Hadi had previously said that he was open if Najib wanted to stump for PAS in the Seri Setia by-election.

The PAS president said there were "positive developments" on the Seri Setia campaign trail, claiming that Pakatan Harapan's support was sliding.

"The core Umno support is with us. If we combine our support and considering the voting trends in the previous Sungai Kandis by-election, there could be a change," he said.

Umno had decided not to contest in the Seri Setia by-election to make way for PAS.

PAS' Dr Halimah Ali is contesting against PKR's Halimey Abu Bakar under the Pakatan Harapan banner, the first time the coalition's logo will debut in an election.

In the 14th general election, PKR won the Seri Setia seat by a landslide, garnering 29,250 votes to BN's 9,878 votes and PAS' 4,563 votes.

The seat fell vacant after its incumbent Shahruddin Badaruddin passed away from cancer.