The reasons for this biggest-ever by-election in Singapore's history were the demise of PAP Member of Parliament for Anson, P. Govindaswamy, as well as the resignations of six veteran PAP Ministers and MPs in the ruling party's continued initiative to renew its ranks. Although key opposition stalwarts emerged to contest, BS stayed away and this decision was criticised by UPF.

Nomination day: 31 January 1979 [Wed]
Polling day: 10 February 1979 [Sat]

Eligible voters: 116,881
Voters in walkover constituencies: 36,806 (31.5%)
Total voters: 80,075 (68.5%)
Total voter turnout: 74,887 (93.5%)

Election deposit: $1,200

RESULTS
Anson	Geylang West	Mountbatten	Nee Soon
Potong Pasir	Sembawang	Telok Blangah
Total seats = 7