the SDP
/ði ˌes diː ˈpiː/
/ði ˌes diː ˈpiː/
the Social Democratic Party
- a British political party formed in 1981 by a group of Members of Parliament who left the Labour Party to start a new 'middle party' in British politics. In 1987 it combined with the Liberal Party to form the Liberal Democratic Party . A small group led by David Owen continued to call themselves the SDP until 1990.