During this time, the mostly ethnically Chinese rebels under the leadership of the Malayan Communist Party launched guerrilla operations designed to force the British out of Malaya. The Malayan Emergency (1948–1960) involved a long anti-insurgency campaign by Commonwealth troops in Malaya. On 31 August 1957, Malaya became an independent member of the Commonwealth of Nations. After this a plan was put in place to federate Malaya with the crown colonies of North Borneo (which joined as Sabah), Sarawak, and Singapore. The date of federation was planned to be 31 August 1963 so as to coincide with the anniversary of Malayan independence; however, federation was delayed until 16 September 1963 in order for a United Nations survey of support for federation in Sabah and Sarawak, called for by parties opposed to federation including Indonesia's Sukarno and the Sarawak United Peoples' Party, to be completed.