Deputy Prime Minister Tharman Shanmugaratnam assured Bukit Batok residents last night that their needs would be tended to even though their MP had resigned.
"We will make sure that problems are solved, that their needs are taken care of, that all the projects that are ongoing carry on smoothly and are completed," he told reporters.
He also said that the People's Action Party (PAP) had a few "very strong candidates" it was looking at to replace Mr David Ong, who stepped down two days ago over an alleged affair.
"We are quite fortunate to be in that position. When we finally announce the candidate, I can assure you it will be someone committed to the interest of Bukit Batok residents, and who will be able to also speak for them and Singaporeans in Parliament," he added.
Prime Minister Lee Hsien Loong had, in announcing Mr Ong's resignation last Saturday, also said he would call a by-election for the single seat "in due course".
Speaker Halimah Yacob also confirmed she had received Mr Ong's resignation and declared his seat vacant at the start of yesterday's Parliament sitting.
Yesterday, Mr Tharman, an MP for neighbouring Jurong GRC, turned up at the weekly Monday night Meet-the-People Session at the PAP Bukit Batok branch, which began at 7.30pm as usual.
Jurong GRC MP Ang Wei Neng was there to see to residents who needed help, accompanied by PAP Bukit Batok branch secretary Leow Boon Swee, who some see as a possible candidate. Senior Minister of State Desmond Lee, who has been tasked to look after the constituency for now, is abroad for work.
At least 30 residents turned up at the Meet-the-People Session last night, some of whom were not aware that Mr Ong had resigned.
One of them was factory worker Aesha Amat, 64, who said: "If you made a mistake, you should come out and say 'sorry'. You cannot just suddenly quit and then go missing in action."
Technician Francis Ng, 51, however, noted that he had approached Mr Ong in person a few times.
"He's very polite, quite easy to talk to and can connect with residents. He doesn't give off a haughty vibe," he said in Mandarin.
But Mr Ng added that he did not think Mr Ong handled the matter well, and that he should have come out to apologise publicly.
Told that some residents had hoped Mr Ong would address them and explain his actions, Mr Tharman said Mr Ong needed his privacy now and would have to decide for himself when to reappear in public.
Mr Ong yesterday told The Straits Times via e-mail: "I have expressed my deep regret and acknowledged my personal indiscretion. It would be best to leave it at that."
He also thanked the Bukit Batok residents for the strong support they had given him.
"I have done my best to perform my responsibilities, and deeply apologise to them for having to step down prematurely," he added.
Yesterday, Workers' Party (WP) chairman Sylvia Lim told reporters at her Meet-the-People Session in Aljunied GRC's Serangoon ward that her party will not contest the Bukit Batok by-election.
She cited two reasons: The WP is not active in that area, and the Singapore Democratic Party (SDP) had declared at the weekend its intention to run, having contested the single-member constituency in last year's general election.
The SDP received 26.4 per cent of the vote in that contest. It held a walkabout on Sunday in Bukit Batok, and party chief Chee Soon Juan said there was a possibility he might run as the SDP was still considering who to field.