But could the redrawn boundaries tip the scales in the opposition's favour? MacPherson, which polled second-highest out of five Marine Parade wards last time, will now be a single seat.

Meanwhile, the contentious Joo Chiat single seat, where the Workers' Party (WP) lost by just 388 votes, has been absorbed into the GRC.

Mr Tan tells Insight that his team's focus remains the same - helping residents and building community ties. He says: "In many ways, there's no particular strategy. Are we doing anything different? No. The work goes on, regardless of who comes."

This time, his team faces a new contender: the WP. The NSP has agreed not to contest in the interests of "opposition unity".

WP chief Low Thia Khiang says the party will contest Marine Parade given its absorption of Joo Chiat, so as not to "disappoint voters in Joo Chiat who have supported us at the last election".

Its candidate was businessman Yee Jenn Jong, 50, who cast himself as a local-boy-made-good. He has been seen in recent weeks during walkabouts in the GRC.

Mr Yee's potential appeal has not gone unnoticed.

His rival in the 2011 polls, the PAP's Mr Charles Chong, tells Insight: "He grew up in that area. His parents had many friends, people who helped him with the election. Some residents told me it's hard to say no to him. He had home-ground advantage."

Indeed, Mr Goh, 74, said in a jibe on Facebook last month: "My mother used to bring me to visit her mother at Frankel Estate when I was a boy... You can say I knew Frankel Estate, a part of Joo Chiat, before the local boy was born."

WHAT HAS CHANGED?

Contributing to the close fight in 2011 was the charisma of NSP's youthful star-catch Nicole Seah, in contrast to the public hostility aimed at PAP new face Tin Pei Ling.

Mr Goh said in the aftermath of 2011: "My team and I have heard the voices of all voters clearly, and we will work with you on all the issues raised." One step he took was to get closer to the ground. After stepping down from the Cabinet, Mr Goh began visiting other wards and hosting his own Meet-the-People Sessions (MPS) regularly.

Several community schemes have also been launched, with infrastructure works such as the Housing Board's Home Improvement Programme for old flats.

In his Kembangan-Chai Chee ward, for example, Mr Tan has started a programme that tutors and mentors children from low- income families; another project helps rental flat residents avoid bedbug infestations through regular pest control, flat cleaning and refurnishing.

While some of the 100 residents polled by Insight note these efforts, many say municipal issues generally do not affect their votes.

Taking the eagle-eye view is Geylang Serai resident Prem Kumar Nair, a 56-year-old material planner, who says: "There are many issues crucial to the election. It's never-ending. Cost of living is high, of course, but you've got to work hard and spend frugally. Things won't change."

OPPOSITION OPPORTUNITIES

Think of Marine Parade, and images of Housing Board flats opposite East Coast Park that enjoy the sea breeze come to mind.

But the GRC stretches about 15km inland to Braddell Heights near Serangoon - a former single seat that was absorbed in 1997 after the PAP got 52.3 per cent of the vote in 1991.

Some residents feel little connection to the rest of the GRC.

It borders former opposition ward Potong Pasir and current WP-held Aljunied GRC, and Braddell Heights is seen by some as an opposition gateway.

"This area is likely to support WP," a resident who wants to be known only as Mr Lim tells Insight as he enjoys a drink with friends from WP stronghold, Aljunied GRC. Adds the 60-year-old semi-retiree: "They keep expanding their territory (out from Hougang)."

The ward also has a large share of private housing - such residents are generally more open to voting for the opposition.

While some credit PAP incumbent Seah Kian Peng with improvements such as new street lights and pavements, half of the dozen private housing residents polled in Braddell Heights said they were undecided, or considering the opposition. But none has seen any opposition parties walking the ground.

Adding to the mix is the Joo Chiat ward, which comprises virtually only private housing. Residents said a sore point in 2011 was the PAP being seen to have parachuted in veteran MP Charles Chong at the last minute to replace retiring incumbent Chan Soo Sen.

Mr Chong, who was then MP for Pasir Ris-Punggol GRC, was introduced as Mr Chan's replacement only 41 days before the 2011 polls.

Since his narrow win, he has worked hard to address both municipal and national gripes, although how this will pay off may be moot as he is expected to contest WP-held Punggol East SMC.

His likely replacement, Mr Edwin Tong, an MP in the dissolved Moulmein-Kallang GRC, has started walking the ground but he may still be an unfamiliar face.

Mr Chong notes: "A high percentage of the vote in Joo Chiat is the pioneer generation. Cost of living, healthcare costs, have a big impact. And if you look at government programmes, growth dividends, GST rebates and so on, those in private housing get nothing. This was a source of unhappiness."

Resident Mona Chen, a banker in her mid-30s, was impressed by how Mr Chong handled her complaint about construction noise near her home. She "gave the WP a chance" in 2011, but says she is likely to vote for the PAP this time, having gained confidence after Mr Chong's work.

Lawyer Rachel Tan, 25, who lives in Joo Chiat, says she is inclined to vote for PAP because "they have done a good job taking care of Marine Parade", citing renovations and improvements like hawker centre and park upgrading.

The WP has its stalwarts, too. Housewife Toh Sin Ai, 52, intends to vote for them again - she feels private home residents like herself have been neglected by the PAP.

But Mr Tan points out: "Now that Joo Chiat is part of Marine Parade GRC, what we will bring to bear is the weight of myself and (Mr Goh). We will certainly look at some of the concerns that they have and address them as best as we can."

For some, the party's familiarity matters most. Says former contractor Toh Soo Kong, 70, who has lived in Joo Chiat for more than 50 years: "I have seen MPs come and go, and most are not memorable. What is memorable is the PAP. Their stability will always lead us."

DO HEAVYWEIGHTS COUNT?

The one constant in Marine Parade GRC, through the elections since 1976, is Mr Goh's looming, patriarchal presence.

Associate Professor Eugene Tan of the Singapore Management University, who lives in Marine Parade GRC, tells Insight that Mr Goh's indication that he will stay on is a "tremendous boost" for the team.

"As a voter, I've observed that ESM Goh has led the PAP's team in winning back voters. His candidacy will provide significant heft, experience, and tactical nous for the PAP's campaign," says Prof Tan, a former Nominated MP.

Political scientist Derek da Cunha predicts a "fairly close fight", saying: "Some segment of voters do not have anything against Mr Goh or his colleagues; it's just that they like WP more. When added to the protest vote against the PAP, (it) would be sufficient for the WP to get to the finish line."

Some residents Insight spoke to, like director of IT Samuel Chia, 42, who lives in Braddell Heights, believes the WP's slate must include a heavyweight for it to stand a chance in toppling the incumbents, adding his vote will depend on the final candidate slates. Of 100 residents Insight spoke to, a fifth are still undecided.

Surprisingly, while Mr Goh has some personal fans among those polled by Insight, most say his presence is not a deciding factor.

Section manager Goh Jin Kiat, 43, who lives in a Housing Board flat in Haig Road, notes: "Mr Goh doesn't run this estate and I've never seen him. He is not the main point of us making the decision."

Meanwhile, MSF Minister Tan's interactions with netizens on social media have elevated his presence. Marketing manager Andrew Zhan, 29, who lives in Mr Tan's Kembangan-Chai Chee ward but has never met his MP, says: "He personally has used social media to reach out and share his views. As such, I can feel his presence and that bolsters my confidence in his ability to be a good minister and MP."

Mr Tan makes at least one post on Facebook a day on average, and is the third-most "liked" Cabinet minister on the platform .

He is also approachable in person, say residents like security screening officer Tamil Selvam. The 59-year-old says Mr Tan's ministerial portfolio is irrelevant to his vote, and what matters more is that he is "very capable and very down-to-earth".

Asked if there is a fear that the PAP might lose Marine Parade GRC, Mr Tan says: "It's not a fear. But is it possible? Why not?

"It's really for residents to decide, from the effort we've put in.

"Leadership is about trust, and although you may not agree with some of our policies, do you trust us, to be prepared to vote and support us to look after you and your family?"

• Additional reporting by Chuan Limin, Rachel Chang and Jasmine Osada