Gordon Brown is considering handing Baroness Vadera — one of his most forceful supporters — Britain’s place on the next European Commission, The Times has learnt.

The appointment would require David Cameron to co-operate with one of Mr Brown’s most controversial ministers if the Tories win the next election. Lady Vadera’s chances of landing a five-year stint in Brussels have risen sharply in recent weeks thanks to lobbying from the current European Commission President, José Manuel Barroso.

Mr Barroso, who is set to serve a second term when the new body is finalised later this year, is urging Mr Brown to nominate a female candidate, senior Whitehall officials say.

The appointment is one of the most significant acts of patronage left to the Prime Minister before the election.

Geoff Hoon, who stepped down as Transport Secretary at the last reshuffle, has made little secret of his desire to fill the post. However, Mr Brown is said by Whitehall officials to be intent on securing a powerful brief on the European Union’s executive body when negotiations begin in earnest. If he becomes convinced that he is more likely to win for Britain the coveted position of Competition Commissioner by nominating Lady Vadera, he will not hesitate to propose his former aide, officials believe.

Mr Brown is well aware of the potential political difficulties he could cause any successor: he inherited Peter Mandelson, Tony Blair’s nomination as EU Trade Commissioner, when he took over at No 10.

The reconciliation between the men created a vacancy when Mr Brown ennobled his former enemy and handed him a powerful role at heart of his Government last autumn. The woman chosen as his stand-in in Brussels, Baroness Ashton, is thought to have only a slim chance of holding on to her job, partly because she lacks the backing of Lord Mandelson.

Lady Vadera, a minister in Lord Mandelson’s Department for Business, Innovation and Skills, is instead emerging as the insiders’ tip.

The appointment would cap an extraordinary career for the former adviser to the investment bank UBS, whose family fled from Uganda to Britain in 1972. She became one of Mr Brown’s most powerful enforcers in her role as one of his special advisers in the Treasury and remains at the heart of his kitchen cabinet.

Her robust style, particularly with civil servants, has become the stuff of Whitehall legend and has won her enemies as well as admirers. If appointed to a five-year term, however, she would be in a powerful position, whatever the outcome of the next election.

Times Recommends

• McDonald’s: the world’s local restaurant
• Illegal migrants should be allowed to stay
• ‘Locking up children doesn’t work’