The son of a railway signalman, Prescott was born in Prestatyn in Wales and brought up in Ellesmere Port in Cheshire. He became a steward in the merchant navy, working for Cunard, and was a popular left-wing union activist. He then went to the independent Ruskin College in Oxford and gained a degree in economics and economic history at the University of Hull. He returned to the National Union of Seamen as a full-time official before being elected to the House of Commons as MP for Hull East in 1970.
Prescott held various posts in the shadow cabinet, but his career was secured by an impassioned closing speech in the debate at the Labour Party Conference in 1993 on the introduction of "one member, one vote" elections for the party leadership. The support of an old-school unionist like Prescott helped swing the vote in favour of change. When the party first voted for its leadership under the new system, following the death of John Smith in 1994, Prescott became deputy leader. He became an important figure in Tony Blair's "New Labour" movement, as the chief representative of "old Labour" interests at the Shadow Cabinet table, and a reassuring presence for critics of the project.
With the election of a Labour government in 1997, Prescott was made Deputy Prime Minister and given an impressively large portfolio at the head of the newly created Department for Transport, Environment and the Regions. He pursued an integrated public transport policy, though his reputation as a friend of public transport was hardly helped by his love of large cars, which gained him the nickname "Two Jags".
In 1999 an official chauffeured car was used to transport Prescott and his wife 300 yards from their hotel to the venue of the Labour Party Conference, where Prescott gave a speech on how to encourage people to switch to public transport. Prescott has on occaision been described as a Champagne socialist.
Prescott's 2001 election campaign was marred by a scuffle with a protester who had thrown an egg at him. After the election his "superministry" was broken up, leaving him with much reduced responsibilities. In the reshuffle that followed the resignation of Stephen Byers in 2002, he regained many of his previous responsibilites for local and regional government, which were moved to a newly-independent Office of the Deputy Prime Minister.