Social Democratic Party (UK)
The Social Democratic Party (also known as the SDP) was a centrist political party that was made by Labour Party politicians in 1981 who did not like how left-wing the party was becoming. The SDP was founded on 26 March 1981 by four senior Labour Party moderates, dubbed the "Gang of Four": Roy Jenkins, David Owen, Bill Rodgers and Shirley Williams.
They allied with the Liberals, winning 25% of the vote in 1983 and 23% in 1987. The alliance between the SDP and the Liberals was called the "SDP-Liberal Alliance". The SDP and Liberals merged in 1988 to form the Liberal Democrats.