By the time this very last election for the Legislative Assembly took place, PAP had become a federal party with a registered entity in the Peninsular. Apart from its 12 appointed representatives in Malaysia's Parliament, PAP contested 11 seats in the 1964 Malaysia General Election and won one. However, this move soured its relations with the ruling Alliance Party of Malaysia, as PAP had defeated SA soundly in 1963. Matters worsened after PAP and several opposition parties established the Malaysian Solidarity Convention on 9 May 1965 to campaign for a "Malaysian Malaysia", which was perceived to be challenging the special position of ethnic Malays. The PAP state government also proposed to the Alliance federal government for a looser confederation consisting of Singapore, Sabah, Sarawak and Penang should differing views on autonomy were difficult to bridge. These factors set the stage for the eventual expulsion of Singapore from Malaysia. Two months before this happened, UPP chief and only Assembly Member Ong Eng Guan resigned his seat against his party's advice, citing the infrequent legislature sessions as the reason. He contemplated running again for the seat but later decided to retired from politics instead. With SA also pulling out from possibly contesting, became a straight fight between the two main parties, PAP and Barisan, and their candidates were former PAP Assembly colleagues. SA surprisingly threw its support behind Barisan, its ideological opposite, but Alliance neither endorsed PAP that it had strained relations with nor a leftist party. The bombing of MacDonald House by two Indonesian soldiers three months earlier on 10 March 1965, as part of President Sukarno's "Konfrontasi" against Malaysia, gained PAP some traction from voters. The soldiers were consequently handed the death penalty. Newly-elected Assembly Member Lee Khoon Choy was sworn in only four months after his victory as a Member of an independent Singapore's first Parliament during its opening. After Singapore's separation from Malaysia, its 15 seats in the federal parliament, including the three appointed from Barisan, ceased. Members of PAP Malaysia, including its lone elected representative C. V. Devan Nair, founded Democratic Action Party when their party was de-registered by the Malaysian authorities. In 1969, Nair quit Malaysian politics and returned to Singapore.

Writ of election: 23 June 1965 [Wed]
Nomination day: 30 June 1965 [Wed]
Polling day: 10 July 1965 [Sat]
Member swearing-in (at 1st Parliament): 8 December 1965 [Wed]

Eligible voters: 11,837
Voter turnout: 10,858 (91.7%)

Election deposit: $500

RESULTS

Hong Lim