The Irish Socialist Network (ISN) is a democratic socialist organisation formed in 2001. It is a campaigning organisation which works actively to fight for the rights of Irish workers and to help build a socialist Ireland. It is based in Belfast and Dublin. Politically, the ISN locates itself within the Marxist tradition, but it rejects both Leninism and Trotskyism, partly because of its opposition to democratic centralist organisational structures and to the concept of the vanguard party, which it deems elitist. Most of the founding members were former members of the Workers' Party, some being involved in the Official Republican Movement split in the late 1990s.