The party was a member of the Labour and Socialist International between 1923 and 1940. Since 1951 the party has been a member of the Socialist International, which was founded thanks to the efforts of the Clement Attlee leadership. However, in February 2013, the Labour Party NEC decided to downgrade participation to observer membership status, "in view of ethical concerns, and to develop international co-operation through new networks". Labour was a founding member of the Progressive Alliance international founded in co-operation with the Social Democratic Party of Germany and other social-democratic parties on 22 May 2013.

When did the Conservative Party downgrade its participation to observer member status?