The Singaporean-based People's Action Party (PAP) had decided to run on the peninsular in response to the United Malays National Organisation (UNMO) participating in the 1963 Singaporean general election, which violated an agreement not to do so, and although the PAP attracted large crowds at its rallies, it won only one seat – Devan Nair in Bangsar at Selangor.

[2] It is thought by some historians that Minister of Finance and Malayan Chinese Association (MCA) President Tan Siew Sin's appeal to the ethnic Chinese in the peninsular to avoid challenging the Malay special rights and risk merger with Indonesia helped the MCA retain its status as the "undisputed leader of the Chinese in the Malayan peninsula" at the time.

Nevertheless, Alliance leaders, especially from UMNO and MCA, were furious with the PAP and would deem them and Lee Kuan Yew's charisma with voters as a threat to their rule.

This was intended to act as a check and balance to prevent parliament from passing constitutional amendments – which required a two-thirds majority – without the agreement of representatives from the three new states.

After Singapore was expelled from Malaysia, Sabah and Sarawak were only left with 28% of the seats (when 40 seats were divided by the remaining 144), and as a consequence both states were not able to stop parliament from approving laws that would erode on their special rights granted upon them as equal partners.