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 PAP to call a second by-election in a year. Through another co-operation among opposition parties, it was BS turn 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