SINGAPORE - The People's Action Party (PAP) is looking at a few "very strong" candidates for the upcoming Bukit Batok by-election, Deputy Prime Minister Tharman Shanmugaratnam revealed on Monday (March 14) night.

"We are quite fortunate to be in that position. When we finally announce the candidate, I can assure you it'll be someone committed to the interest of Bukit Batok residents and who will able to also speak for them and Singaporeans in Parliament," he told reporters.

Asked if the candidate will be a familiar face to residents, he said: "I can't say very much more at this point but fortunately we've got some very good people."

He was at Bukit Batok constituency's Meet-the-People session to make sure everything carried on smoothly.

Mr Tharman's fellow Jurong GRC MP Ang Wei Neng was also at the PAP office there to fill in for Mr David Ong, who resigned as MP on Saturday (March 12).

Mr Ang was filling in for Senior Minister of State Desmond Lee, who is taking charge of the party branch but is overseas on official business and will be back on Wednesday.

Bukit Batok was part of Jurong GRC before it was carved out as a single seat in the general election last year.

Mr Ong, 54, resigned as MP, and from the PAP, due to personal indiscretion. He is believed to have had an extramarital affair with a woman who is a grassroots leader in his ward.

Prime Minister Lee Hsien Loong said on Saturday he will call for a by-election "in due course" but no dates were given. Some analysts believe that it could be held as early as May, soon after Parliament completes its debate on the Budget on April 15.

Mr Tharman on Monday assured residents the PAP had their interests at heart.

He said: "We will make sure that problems are solved, that their needs are taken care of, make sure that all the projects that are ongoing carry on smoothly and are completed."