The prime minister, Gordon Brown, has hired ex-Ofcom chief Stephen Carter as chief of strategy and principal advisor.
Carter, 43, will be in charge of Political Strategy Communications and Research - a job similar to the one carried out by Alistair Campbell during Tony Blair's premiership.
Brown said, "As both a chief executive and industry regulator, he has an enviable track record in the private and public sectors, and will bring his considerable qualities and experience to the work of government."
Carter's appointment follows a career in which he became the first chief executive of Ofcom, the telecoms regulator, and managing director of cable group NTL.
While at NTL, Carter was responsible for the company's businesses in Britain and the Irish Republic. He left with a payoff and bonus of more than £1.6m, even though the company filed for bankruptcy protection.
Carter will stand down from his current role as chief executive of PR firm Brunswick Group with immediate effect.