Purba Banglar Sarbahara Party (Bengali: পূর্ব বাংলার সর্বহারা পার্টি, Bengali for 'Proletarian Party of East Bengal') is a communist party in Bangladesh. The party played a role in the independence struggle of the country. In the early 1970s it engaged in armed struggle supporting the new Bangladeshi state. Since then its political fortunes have dwindled, having suffered from several waves of internal divisions. The group remains active, and still carries out violent attacks against its opponents.
The group emerged from the pro-China trend of the communist movement in erstwhile East Pakistan. In 1967 Siraj Sikder had formed the Mao Tse Tung Thought Research Centre in Dhaka. The Centre was physically attacked by Jamaat-e-Islami cadres at several times. On January 8, 1968 the group formed the Purba Banglar Sramik Andalon ('Workers Movement of East Bengal'). The founding conference lasted, which was completed in a single day, was held in the residence of a jute mill worker in Dhaka. The conference was attended by 45-50 followers of the Centre.
The line of this tendency differed clearly from other pro-Chinese groupings in East Pakistan at the time. Sikdar's faction saw Pakistan as a colonial power, and wanted to struggle for national liberation for East Bengal and the formation of a Democratic Republic of East Bengal. This stood in sharp contrast to official PRC foreign policy, which generally supported Pakistan against India. This line was also more radical than that of the mainstream Bengali nationalist movement. Sheikh Mujibur Rahman denounced the Sikdar faction as 'pro-Chinese provocateurs'.
The group also opposed US imperialism, Soviet social imperialism, Indian expansionism and feudalism.