Murray was commissioned into the King's Shropshire Light Infantry in April 1943 and landed on the Normandy beaches on D-Day. Six days later he was badly wounded and in October 1944 he was invalided out of the Army with the rank of Lieutenant. He was a Trades Union Congress (TUC) employee from 1947, and became assistant general secretary in 1969. He was made General Secretary (leader) of the Trades Union Congress in 1973, and led the group during the time of the Winter of Discontent, and of confrontations with Margaret Thatcher's government.