 Shortly after he was elected to Parliament, Wrigglesworth was a founder member of the Manifesto Group and with John Cartwright helped found the Campaign for Labour Victory under the leadership of Bill Rodgers.From 1974 to 1979, he was Parliamentary Private Secretary to the Home Secretary, the Rt Hon Roy Jenkins, and when Labour returned to Opposition in 1979, he was appointed Shadow Minister for the Civil Service by the Rt Hon James Callaghan.However, Wrigglesworth became increasingly disillusioned by the leftward direction the Labour Party was taking and became part of the nucleus of Labour MPs who contemplated leaving the party in 1979 and 1980.