In 2011, all eyes were on the Workers' Party (WP) on Nomination Day.

Up until then, the party had not disclosed its full slate for Aljunied GRC and it was only on the day itself, when then party chief Low Thia Khiang hopped onto a bus with the Aljunied team, that it became clear he would be the one leading the charge there.

Yesterday, a similar scenario played out in East Coast GRC.

But this time, it was the People's Action Party (PAP) that had kept everyone guessing. With only half an hour left for candidates to file their papers, the ruling party's last candidate for the constituency was still nowhere to be seen.

Then, Deputy Prime Minister Heng Swee Keat's car entered St Anthony's Canossian Primary School, the nomination centre for the constituency, providing a surprise answer to one of the day's biggest questions.

With long-time East Coast MP and former minister Lim Swee Say having stepped down, it was expected that the PAP would send a minister to helm the constituency.

Mr Heng's inclusion appeared to have been made at the last minute - his name was written into the nomination form and not printed like the rest of his team's.

Taking the designated leader of the Government's next generation of leaders out of his own constituency and putting him in one of the most hotly contested GRCs at the last general election was not on anyone's radar, and the move has repercussions for the WP that may last well beyond the July 10 election.

Since the opposition party's first foray into East Coast in the 2006 election, its slate in the constituency has always gotten the most buzz, behind only its team in Aljunied GRC.

In 2015, the candidates fielded in East Coast - Mr Gerald Giam, 42, Mr Leon Perera, 49, Dr Daniel Goh, 47, and Mr Fairoz Shariff, 41 - were touted as the party's next-generation leaders.

Then party chief Mr Low had made an impassioned plea for voters to send them into Parliament. In the end, they fell short with 39.27 per cent of the votes. Still, ever since the WP brought Aljunied into its fold in 2011, it had always seen East Coast as its natural second GRC.

That it is right next to Aljunied GRC provides logistical advantages. East Coast has yielded the WP's best result in a GRC outside of Aljunied in the last three elections.

It has also been the training ground for the party's NCMPs, with Mr Perera, Dr Goh and Mr Giam all entering Parliament through the scheme after being the best losers in the election.

Over the years, the constituency has become an important part of the WP's strategy to expand its base in the east.

And while it withdrew Mr Giam and Mr Perera - the most established names from the East Coast GRC team - to defend Aljunied GRC, it was assumed the retreat was temporary, given the circumstances of this election.

But with the PAP moving its prime minister-designate there, that scrambles the calculus.

If the PAP is to retain East Coast GRC, the WP will have to decide how seriously it wants to challenge what is likely to be the ward of the sitting prime minister.

The party has in the past been careful about presenting itself as a party that wants to unseat the Government. However, if it is then to send its team B elsewhere, it would be sacrificing years of work establishing itself in East Coast GRC.

When asked, WP chief Pritam Singh said yesterday that Mr Heng's candidacy is "an important signal that they take our challenge in East Coast very seriously".

He added: "I would say we take their challenge equally seriously and that's why we've put together a strong slate of candidates in the East Coast team."

Yet, it is undeniable that while the party's East Coast candidates are no slouches, wealth advisory firm director Dylan Ng, 45, Singapore Cancer Society deputy director Kenneth Foo, 43, lawyer Terence Tan, 49, and former researcher and new face Sharif Kassim, 54, just do not have the profile of Mr Giam and Mr Perera.

The only East Coast candidate who has matched the duo in star power is former National Solidarity Party candidate Nicole Seah, 33. Even then, she lacks the Parliamentary and town council experiences they have amassed.

This development has raised the question of whether the WP had miscalculated in revealing its Aljunied GRC slate too early.

Doing so would have given the PAP more room to make its manoeuvres, since it can be confident that the WP will not pull another last-minute switcheroo and move Mr Singh or party chairman Sylvia Lim to East Coast.

Of course, Mr Heng's move may still have happened, regardless.

The WP is going into electoral battle for the first time under Mr Singh and it will be the party's first election since 1991 without Mr Low on its candidate list. WP is also coming off a narrow win in Aljunied GRC in 2015, fuelled in part by the issues raised during the Aljunied-Hougang Town Council saga.

Mr Low has been said to be contemplating retirement and some had speculated that he may move out of Aljunied to make a grab for another GRC, like East Coast.

But the decision for him to step down solidified after he fell at home on April 30 and sustained serious head injuries.

As well, two other stalwarts have also opted not to stand for election - incumbent MPs Chen Show Mao of Aljunied GRC and Png Eng Huat of Hougang.

Having to push ahead with renewal, perhaps partly by choice and partly forced by circumstances, does tie the party's hands, and announcing its Aljunied slate early may be a signal to voters that it is serious about its home turf.

The party's decision to field a new face, contracts administrator Tan Chen Chen, 38, in Punggol West, and team up party veteran and former NCMP Yee Jenn Jong with three fresh faces and one former candidate in Marine Parade, are further signs that this election is about consolidation and defending Aljunied and Hougang.

Punggol West SMC was seen by many as the most likely place for the party to secure a seat and there had been speculation that it may have sent Ms Lim or Ms Seah there.

For now, the most talked about WP team is its Sengkang slate, comprising corporate counsel He Ting Ru, 37, economist Jamus Lim, 44, equity research analyst Louis Chua, 33, and social activist Raeesah Khan, 26.

Some have even called this the party's Team B this election, though only Ms He has been a candidate and the rest are new faces.

Perhaps knowing that the PAP will defend East Coast strongly, the party had already made a gamble to find another GRC to sink its roots.