The Manifesto Group

The Manifesto Group was a parliamentary alliance of British Labour MPs led by Dickson Mabon (who preferred to be known as 'Dick Mabon'), who were opposed to what they perceived to be the leftward drift of the Labour Party in the 1970s.

In 1974, the hard-left Labour MP Ian Mikardo was elected as chairman of the Parliamentary Labour Party. Dickson Mabon was opposed to this, as he saw it as evidence of a drift towards the hard left. As a result, he launched the Manifesto Group of Labour MPs on 17 December 1974, to counterbalance it and to support Labour MPs who "did not regard defending the [Labour] Government as a betrayal of socialism".

Membership of the Manifesto Group included John Smith, Denis Healey, George Robertson, Roy Hattersley, Gerald Kaufman and Jack Cunningham. It also included Brian Walden, David Marquand, John Horam, Ian Wrigglesworth, the then Father of the House George Strauss, the former Foreign Secretary Michael Stewart, Ben Ford,Giles Radice and Phillip Whitehead. It also included many members who were later to defect to the SDP, such as Roy Jenkins, Bill Rogers, Shirley Williams and David Owen, including Dickson Mabon himself.

...
Wikipedia