Deputy Prime Minister Teo Chee Hean said on Saturday the People's Action Party (PAP) will remain focused on serving residents on the ground, even as an opposition party made proposals to avoid a multi-cornered fight.

He would only say this when asked to comment on the Singapore Democratic Party's (SDP's) proposal to Workers' Party to field a single candidate.

He said residents' concerns are about issues related to day-to-day living and their surroumdings such as transport.

The PAP has tried its best to address these concerns, including those raised by residents when meeting their MP.

Mr Teo was speaking to reporters on the sidelines of a community event in Sengkang for Neighbourhood Watch Day.

A by-election was called on Wednesday in Punggol East, whose former MP and Speaker Michael Palmer had resigned over an extra-marital affair.

On Thursday, the PAP formally introduced its candidate, surgeon Koh Poh Koon, 40.

Last night, the SDP announced fresh overtures to the Worker's Party to field a single candidate together to avoid a multi-cornered fight.

It proposed fielding a candidate from SDP to raise issues in Parliament, but the WP will run daily operations of the town council.

Both parties have yet to introduce their candidates.

Nomination Day will be on Wednesday, and Polling Day on Jan 26.