 He served as Chairman of the Labour Party in 1971 – 72 while in opposition , and in the Labour Government of 1974 – 1979 , he returned to the Cabinet , initially as Secretary of State for Industry , before being made Secretary of State for Energy , retaining his post when James Callaghan replaced Wilson as Prime Minister . When the Labour Party was again in opposition through the 1980s , he emerged as a prominent figure on its left wing and the term " Bennite " came into currency as someone associated with radical left @-@ wing politics . 
