SINGAPORE - The Reform Party (RP) has announced that it will no longer contest West Coast GRC, avoiding what was set to be a three-cornered fight with the People's Action Party and the Progress Singapore Party (PSP).

Barely a day into the 17-day election period, RP secretary-general Kenneth Jeyaretnam announced in the wee hours of Wednesday (June 24) that his party has withdrawn from contesting the group representation constituency after "long talks" with Dr Tan Cheng Bock.

This means that Dr Tan will now be leading his PSP into a head-to-head fight with the incumbent PAP team in West Coast, likely to be anchored by Minister for Communications and Information S. Iswaran.

This latest development comes after Mr Jeyaretnam unveiled six candidates on June 15 for the upcoming general election, half of whom had been part of RP's 2015 team in West Coast, thus raising expectations of a three-cornered fight.

But at about 1.30am on Wednesday, Mr Jeyaretnam said that despite feeling a "strong emotional connection" to West Coast, his party decided the "greater cause" at the moment was opposition unity and contesting where everyone has the greatest chance of winning seats.

"We also recognise that Dr Tan (Cheng Bock) has a tough fight on his hands despite it being his old stomping ground and we do not wish to hinder his progress," he said in a Facebook post.

The PAP defeated the RP in West Coast in 2015 and 2011, and has won every election there since the constituency was formed in 1997.

But Dr Tan has also frequently spoken of West Coast as his "home" ground. It contains the former single-seat Ayer Rajah ward, where he was the PAP's MP for six terms until it was absorbed into the GRC in 2006.

Speaking to reporters on Wednesday morning, Dr Tan said the opposition parties were all on good terms.

"I must really thank RP for not contesting West Coast. We all understand the implications of a three-cornered fight so we can put our differences aside and contest with the PAP one-on-one," said Dr Tan, speaking after a meeting where he announced Mr Lee Hsien Yang - brother of Prime Minister Lee Hsien Loong - as a new party member.

Mr Jeyaretnam said that the PSP offered to withdraw from various areas it had been eyeing in return for West Coast, and the RP has selected its areas based on "moving aside for Dr Tan's A team" and where it thinks it can more likely win.

These are the Radin Mas and new Yio Chu Kang single-member constituencies, and Ang Mo Kio GRC.

"I do hope that all opposition supporters in Singapore will appreciate our decision and come forward to help us in those three areas where we are contesting," said Mr Jeyaretnam.

On Tuesday, the PSP further trimmed the number of candidates it was fielding to 24, after earlier cutting down to 29 from the 44 initially announced.

It added that it would contest nine constituencies - with Yio Chu Kang SMC among them. Dr Tan did not say on Wednesday if PSP will now withdraw from the ward to avoid a potential multi-cornered fight with the RP.

In a Facebook post at about 2.30am on Wednesday, the People's Power Party said it welcomed the RP's decision, adding that it "will be most willing to take a step back" for the RP to focus on Radin Mas, which contains Anson.

The former SMC was helmed by Mr Jeyaretnam's late father, veteran opposition leader and RP founder J.B. Jeyaretnam.

Additional reporting by Kok Yufeng