With the return of British rule at the end of World War II, the Malayan Union was established to bring about unitary control over the whole peninsula. This policy was wholly rejected by native Malayans, including the Parti Kebangsaan Melayu Malaya, who subsequently established the Federation of Malaya in a return to federalism. However, the continuation of British rule was untenable to the MCP, which established the Malayan National Liberation Army to carry out attacks against British colonists. After the MNLA assassination of three British farmers, the colonial administration invoked a state of emergency in Malaya, igniting a civil war between the Federation and the Communists. The administration launched a crackdown on all left-wing political groups, declaring the PKMM and MCP to be illegal. The right-wing United Malays National Organisation subsequently became the ruling political party in the country, cooperating with the British to defeat the communist insurgency. Meanwhile, the PKMM was reorganized as the Parti Rakyat Malaysia, which rejected UMNO rule and cooperated with the Labour Party of Malaya to revitalize the Malayan left-wing.