The origins and development of the SP The history of the Socialiststische Partij (SP) starts with the establishment of the Kommunistische Eenheidsbeweging Nederland/marxistisch-leninistisch (Communist Union Movement Netherlands/Marxist-Leninist, KENml). 1 Inspired by the ideas of Mao, the KENml took action against bad housing conditions and low salaries. While the party gained popularity among workers and students, it was also marked by internal tensions. Gradually, two factions had developed: a proletarian wing under the lead of Daan Monjé and a more intellectual wing symbolized by Kees de Boer. The proletarian wing adhered to the so-called mass line or the Maoist principle of spreading among the masses to learn from them. This contrasted with the idea of a vanguard party which was popular among the intellectual wing. Relations between both groups reached breaking point in the summer of 1971. The KENml split and a majority of its members decided to follow Monjé to the new Kommunistiese Partij Nederland/Marxisties-Leninisties (Communist Party Netherlands/Marxist-Leninist, KPN/ML). On 22 October 1972, the KPN/ML was renamed and the SP was offi cially established (Kagie, 2006; Voerman, 1987).