An UMNO Supreme Council member Tuesday advised the opposition PAS, PKR and Amanah to field their respective candidates in the Sungai Besar and Kuala Kangsar parliamentary by-elections to show their mettle.

"They do not have to negotiate whom to field. Let them show their mettle. Let the people determine who is great," Datuk Shamsul Anuar Nasarah told reporters at the Parliament lobby.

Shamsul Anuar, who is the MP for Lenggong, said the absence of collaboration between PAS and PKR would be to Barisan Nasional's advantage.

As of now, PAS insists on fielding candidates in the two by-elections and Amanah has offered to contest the seats for Pakatan Harapan.

PKR wants to negotiate with PAS on the candidates while DAP has closed the door to negotiations with PAS.

Asked about the BN's chances of retaining the two seats, Shamsul Anuar said the BN won the seats with only a small majority in the general election in 2013 but the situation had changed now.

"The BN has brought about much change for the better in the constituencies," he said.

In 2013, Datuk Noriah Kasnon won the Sungai Besar seat with a 399-vote majority, beating Mohamed Salleh M. Hussin of PAS.

Wan Mohammad Khair-il won the Kuala Kangsar seat with a 1,082-vote majority, defeating Khalil Idham Lim Abdullah of PAS and Independent Datuk Kamilia Ibrahim.

The by-elections are being held following the deaths of Noriah, who was deputy plantation industries and commodities minister, and Wan Mohammad Khair-il in a helicopter crash in Sarawak on May 5. Four other people also died in the mishap.

Nominations for the by-elections are on June 5.