Member of Parliament Lim Guan Hoo suffered a stroke on 13 February 1977, one day prior to the death of another fellow PAP MP, N. Govindasamy. His seat was vacated on 30 June 1977, which precipitated a second by-election in the year. Through another around of co-operation between opposition parties, it was the turn of BS this time to field its leader, political veteran Dr Lee Siew Choh.

Writ of election: 5 July 1977 [Tue]
Nomination day: 13 July 1977 [Wed]
Polling day: 23 July 1977 [Sat]
Member swearing-in: 2 September 1977 [Fri]

Eligible voters: 16,994
Voter turnout: 16,482 (97.0%)

Election deposit: $1,200

Bukit Merah
Total seats = 1