John Reid is seen by his government colleagues as a trusted hard man of New Labour. Whenever the government is on the ropes, it is usually Mr Reid that is sent out to tour the television studios and give insolent journalists at least as good as he gets.
Though he had a two-year spell in the Communist Party, most of his career has been spent working for Labour in various roles, including a stint as an adviser to Neil Kinnock at the time the Labour leader was turning round his party's policies on nuclear disarmament and withdrawing from the European Union.
It was the perfect background for the job of defence spokesman, which he held for years in opposition after he entered the Commons in 1987, and in government after 1997.
In 1998 he was moved to transport. He then moved into the cabinet as Scottish Secretary, before moving to Northern Ireland. A short but successful spell as Labour chairman came next, followed by his latest change of job.