Deputy Prime Minister Teo Chee Hean said the Punggol East by-election will be a close fight.
Speaking to reporters at the Nomination Centre at North Vista Secondary School, Mr Teo said: "I expect that it will be a close fight... what we need to do is to go out and reach out to as many residents as possible. Residents will choose who can best represent them and their interests," he said.
The incumbent People's Action Party (PAP) is fielding a new face in surgeon Dr Koh Poh Koon in the single-seat ward. He is up against three other candidates in a four-cornered fight - the first such contest in a parliamentary election since 1997.
When asked what his campaign strategy will be, Dr Koh said simply: "Listen more, empathise more, and interact more."
"Over the next few days, the residents will get to know me better," he said, pledging to further his efforts in reaching out to residents.
Dr Koh added that the neighbouring Pasir Ris-Punggol GRC MPs have been supporting him, and DPM Teo's advice to him was: "To work as a team and continue working for the residents of Punggol East."
Mr Teo himself entered politics via a by-election. When asked what advice he could give, he said: "Continue what he (Dr Koh) has done.... Over the next few days, he will reach out to as many as he can. He's a down to earth, sincere person... who can make their lives better, and Punggol East better."
The other three candidates in the by-election are: Ms Lee Li Lian of the Workers' Party, Mr Kenneth Jeyaretnam of the Reform Party and Mr Desmond Lim of the Singapore Democratic Alliance.