He attended Taunton's Grammar School as a youth and graduated from the University of Southampton with a degree in Economics.
Once he returned to the House of Commons, Mitchell quickly re-established his reputation as a "classic trades-union rightist" within the Labour Party.
He was a firm Atlanticist and a stalwart defender of the constitutional monarchy, but was also in favour of the nationalisation of Britain's ports.
He acted as consultant to B.A.T Industries Ltd, part of British American Tobacco, which was a substantial employer in the Southampton area at the time.
When he left, he cited his opposition to "further nationalisation, import controls and withdrawing Britain from the Common Market."
He tried for selection as SDP candidate for the 1984 Portsmouth South by-election but lost out to Mike Hancock who went on to win the seat.