In a surprise turn of events, the Singapore Democratic Party (SDP) announced on Tuesday that it will not be contesting the Punggol East by-election.

Secretary-general Chee Soon Juan made the announcement at a press conference at the party headquarters, one day before Nomination Day.

As recently as Monday night, Dr Chee had indicated the party would contest when he told reporters that the SDP had decided on which candidate to field.

An SDP member also collected a political donation certificate earlier on Tuesday. Party activists have also been distributing flyers in Punggol East every night since the writ of election was issued last Wednesday.

The SDP had also tabled a proposal to the Workers' Party (WP) to field a unity candidate, which the WP rebuffed. SDP had then said over the weekend it would proceed "full steam ahead" with its plan to contest.

Dr Chee said at the press conference that he was heeding the call from the public to respect opposition unity.