Driven by emotions and anger towards PAS, both DAP and Parti Amanah Negara (Amanah) turned their backs on Selangor Menteri Besar Azmin Ali's plan to capture the Sungai Besar parliament seat, an Umno MP said.

Shahrir Abdul Samad, who heads the BN Backbenchers Club (BNBBC), claimed that Azmin and former prime minister Dr Mahathir Mohamad were right from a strategic perspective that a straight fight in the by-election would have a more favourable outcome for the opposition.

However, Shahrir said, even PKR and its president Dr Wan Azizah Wan Ismail had ignored the party deputy president on this matter.

"Azmin surely saw PKR as being able to challenge the BN candidate.

"With the state government machinery and support from DAP, Amanah as well as PAS, he believed PKR can engage in a straight fight with BN," he was quoted as saying by the BNBBC portal.

Shahrir (photo) claimed this was what led to the claim about the menteri besar issuing an ultimatum to PAS not to contest in Sungai Besar.

Azmin has since denied ordering the three PAS exco members in his state government to quit, should their party contest.

Meanwhile, Shahrir said it was unfortunate for Azmin that Amanah, which the Umno lawmaker described as a "DAP proxy", obtained support from Wan Azizah to field their candidates.

"It is strange that Wan Azizah, as opposition leader and party president, never gave thought to Azmin's strategy in deciding who should contest.

"I believe Azmin is definitely disappointed with this situation, apart from the pressure from DAP, PAS and the supporters of Wan Azizah within PKR," he added.

Shahrir also said it would be good if Azmin united his group with Mahathir, given his strong support for the Citizens' Declaration.

The Sungai Besar seat is seeing a three-cornered fight among BN's Budiman Mohd Zohdi, Dr Abdul Rani Osman of PAS and Amanah's Azhar Abdul Shukur.

The June 18 by-election was called following the death of its incumbent, Noriah Kasnon, in a helicopter crash in Sarawak.

In the last general election, Noriah defeated her PAS rival by a mere 399 votes.