Prime Minister Lee Hsien Loong says he is considering seriously if a by-election should be held for the Punggol East single-member constituency, and if so, when to hold one.
The parliamentary seat in Punggol East fell vacant following the resignation of the MP for the area Michael Palmer.
Mr Lee was replying to questions from the Singapore media at the end of his visit to India on Friday.
The prime minister said he was very surprised and saddened by what had happened in the case of Mr Palmer.
Mr Lee said that it was quite clear that once the PAP understood what had happened, Mr Palmer had to resign.
The former Speaker of Parliament resigned from the PAP and his MP post earlier this month, after revealing to Singaporeans that he had an extramarital affair with a former staff member of the People's Association who was working in the Pasir Ris-Punggol constituency office.
On reports that four opposition parties have expressed interest to contest a by-election in Punggol East, Mr Lee said: "Well, I haven't decided when to hold the election or whether to hold the election and if so when. If I decide to hold, then it is within the right of any candidate from any of the opposition parties to come and it is up to the voters to decide whom they want to support.
"From the PAP's point of view, of course we will field the best possible candidate, and work our utmost to win and retain the voters' support in Punggol East. As to what sort of candidate we field, we will find the best possible person, but we are serious in our requirements and it is not easy to produce a rabbit out of a hat."
On calls for a legal timeline for a by-election, Mr Lee explained that he had expressed his view on the matter in Parliament a few years ago.
He explained again why it is right that Singapore does not have a time limit for a by-election or an absolute requirement that a by-election be held.
Mr Lee said: "There is a reason for it, because you are electing a team to represent you when you are going to a general election and not just electing an individual in that constituency, but really you are electing a member of a government and the person stands wearing a logo representing a political party.
"Really, the right way to choose a government is in a general election when the choice is put and that choice is really for the term of the government, unless there is a complete change in Parliament. Otherwise, individual MPs, whether they resign or something happens to them, ought not to be able to upset the overall political situation, and that's the reason why it is designed like this.
"Of course, in a practical situation, if you do have a vacancy, if there are no special reasons one way or the other, then there would be expectations you ought to have a by-election to fill the seat, and that's something which I will consider.
"We are different, because we started off different when we went into Malaysia. When we were in Malaysia, we complied with the Malaysian norms, and in the light of the experience we had during that period, after we left Malaysia, we changed back to what we were before the Malaysian period, because we did not want in a tight situation, one person deciding to resign and therefore forcing the government to change.
"Why should one person decide what really should be decided by the electorate as a whole. So there is a reason for that. You may accept it to a certain degree, you may have a view, but it is not something that is accidental."
Asked if he had decided on the next candidate for the post of Speaker of Parliament, Prime Minister Lee said the House will have the name of the candidate in time for the next sitting of Parliament on 14 January.
Mr Lee said that the Speaker of Parliament is elected by the House.
So, Mr Lee said, it is right that when the candidate is decided upon, PAP MPs would be informed first, and thereafter the person would be made known.
The parliamentary seat in Punggol East fell vacant following the resignation of the MP for the area Michael Palmer.
Mr Lee was replying to questions from the Singapore media at the end of his visit to India on Friday.
The prime minister said he was very surprised and saddened by what had happened in the case of Mr Palmer.
Mr Lee said that it was quite clear that once the PAP understood what had happened, Mr Palmer had to resign.
The former Speaker of Parliament resigned from the PAP and his MP post earlier this month, after revealing to Singaporeans that he had an extramarital affair with a former staff member of the People's Association who was working in the Pasir Ris-Punggol constituency office.
On reports that four opposition parties have expressed interest to contest a by-election in Punggol East, Mr Lee said: "Well, I haven't decided when to hold the election or whether to hold the election and if so when. If I decide to hold, then it is within the right of any candidate from any of the opposition parties to come and it is up to the voters to decide whom they want to support.
"From the PAP's point of view, of course we will field the best possible candidate, and work our utmost to win and retain the voters' support in Punggol East. As to what sort of candidate we field, we will find the best possible person, but we are serious in our requirements and it is not easy to produce a rabbit out of a hat."
On calls for a legal timeline for a by-election, Mr Lee explained that he had expressed his view on the matter in Parliament a few years ago.
He explained again why it is right that Singapore does not have a time limit for a by-election or an absolute requirement that a by-election be held.
Mr Lee said: "There is a reason for it, because you are electing a team to represent you when you are going to a general election and not just electing an individual in that constituency, but really you are electing a member of a government and the person stands wearing a logo representing a political party.
"Really, the right way to choose a government is in a general election when the choice is put and that choice is really for the term of the government, unless there is a complete change in Parliament. Otherwise, individual MPs, whether they resign or something happens to them, ought not to be able to upset the overall political situation, and that's the reason why it is designed like this.
"Of course, in a practical situation, if you do have a vacancy, if there are no special reasons one way or the other, then there would be expectations you ought to have a by-election to fill the seat, and that's something which I will consider.
"We are different, because we started off different when we went into Malaysia. When we were in Malaysia, we complied with the Malaysian norms, and in the light of the experience we had during that period, after we left Malaysia, we changed back to what we were before the Malaysian period, because we did not want in a tight situation, one person deciding to resign and therefore forcing the government to change.
"Why should one person decide what really should be decided by the electorate as a whole. So there is a reason for that. You may accept it to a certain degree, you may have a view, but it is not something that is accidental."
Asked if he had decided on the next candidate for the post of Speaker of Parliament, Prime Minister Lee said the House will have the name of the candidate in time for the next sitting of Parliament on 14 January.
Mr Lee said that the Speaker of Parliament is elected by the House.
So, Mr Lee said, it is right that when the candidate is decided upon, PAP MPs would be informed first, and thereafter the person would be made known.