Christians on the Left, formerly known as the Christian Socialist Movement (CSM), is a socialist society affiliated to the British Labour Party.
The CSM was an amalgamation of the Society of Socialist Clergy and Ministers and the Socialist Christian League. R. H. Tawney made one of his last public appearances at the Movement's inaugural meeting on 22 January 1960. Donald Soper chaired the Movement until becoming its President in 1975. In August 2013 it announced that following a consultation with its members it would be changing its name to Christians on the Left
The movement fulfilled a need among Christian socialists in Britain for an organisation that would be politically engaged and theologically reflective at the same time. It affiliated to the Labour Party in 1988.
The CSM was a volunteer organisation until 1994 when it appointed a co-ordinator, followed by an administrator. This followed interest in the movement following the disclosure that the then Labour Leader John Smith was a member. The organisation held an annual church service on the Sunday morning before Labour Party Conference while Tony Blair was leader at which Blair, who was a member, appeared.
Today Christians on the Left has over 40 members in the House of Commons and House of Lords, including former prime minister Gordon Brown. As of April 2016, its Director was Dr Andrew Flannagan; its Executive Committee Chair was Jonathon Reynolds MP; its Vice Chair was Shona Elliott.
Christians on the Left is a member organisation of the International League of Religious Socialists.