Soon after Punggol East MP Michael Palmer quit politics last month, Dr Koh Poh Koon received a call to go to the Istana to meet Prime Minister Lee Hsien Loong.
He knew what was on the agenda: Would he stand as the People's Action Party's candidate in the single-seat constituency?
Dr Koh, who had been invited to a PAP tea session in the middle of last year, quickly consulted friends and family.
Many told him not to take the plunge into politics.
"Everyone felt that it was hard to be yourself and be honest, and still do good," Dr Koh, a colorectal surgeon, told The Straits Times yesterday.
A self-described "troublemaker", he had criticised certain government policies during a meeting with PAP leaders.
Friends were concerned that agreeing to wear the PAP whites would require him to toe the party line, even when he disagreed with it.
He shared their fears: "I don't want to change. I don't want to do populist politics. I want to do real work."
That was the reason he told Mr Lee politely at their meeting that he felt he was not suitable for the task. But the Prime Minister, who is the PAP's secretary-general, asked him to think about it, related Dr Koh.
The 40-year-old had intended to return and say "no" again. He was, however, wracked by guilt over the next few days.
"I thought by saying 'no', I would sleep better. The whole week before that, I was struggling with the answer.
"I felt I had turned my back on society, and that I was being selfish," he said, pausing often and struggling to describe his inner conflict.
Since his school days, he said, he had felt a strong sense of wanting to serve Singapore. He has been involved in grassroots work since 2002, and is a battalion commanding officer for his reservist duties.
He discussed his concerns with his wife, also a specialist doctor, thought hard about it and decided to say "yes" to Mr Lee.
"She knows what kind of person I am. That if the button is pressed today, I will say goodbye to my family, take my gun, and go. Serving the country is a higher calling," said the father of two daughters, aged four and nine.
"Saying 'yes' would be the harder thing, but it would be the right thing. I could sleep better."
Since his unveiling as a PAP candidate a fortnight ago, he has been criticised online.
He was initially demoralised. "Even my wife said, 'See, you want to help people, but they don't want your help'."
But he has come to terms with the fact that there will always be negative remarks, and now pays less attention to them.
He maintains he will continue to be himself. "I'm hoping that with time I will not change. If I do, I'll have no more value being here."