Mr Blair has long favoured Mr Patten, the former Hong Kong governor, for the post. The Prime Minister is keen to install left-wing Tories in key positions and Mr Patten is seen as a more heavyweight figure than Sir Alistair, who is likely to be compensated with a less-prominent job in Mr Blair's gift.
The appointment of Mr Patten, to be announced formally later this month, has ruffled the feathers of Neil Kinnock, Britain's other European commissioner. It is understood that Downing Street has reassured Mr Kinnock he will become Britain's "senior representative" in Brussels because he is from the governing party and has already served a five-year term as a commissioner. Mr Kinnock, the former Labour leader who is now EU Transport Commissioner, is likely to become a vice-president of the Commission, which would give Britain two powerful positions in Brussels.
Mr Patten is probably hoping for an economic job, which could cloud the prospects of Mr Kinnock, who has been pressing for an important foreign affairs portfolio, possibly covering the EU's enlargement. One source suggested that, in addition to being a vice-president, Mr Kinnock could assume a more political, "chief whip" role which included liaising with the European Parliament. That could be a powerful position, though not necessarily Mr Kinnock's preferred one.
The two men were adversaries in the 1992 general election and there is little rapport between them. Mr Kinnock believed that Mr Patten opposed his appointment to Brussels by John Major - a charge denied by Mr Patten.
The appointment of Mr Patten will be seen as a sign that the new Commission president, former Italian prime minister Romano Prodi, is serious about changing the culture of Brussels and beefing up the calibre of his team.
And it provides another signal of Mr Blair's eventual desire to bring sterling into the single currency, to which the former governor of Hong Kong has warmed. Mr Patten has criticised Mr Hague's policy of ruling out monetary union in this Parliament and the next.
Mr Hague refused to rise to Mr Blair's bait yesterday, suspecting that Mr Patten's appointment was leaked in an attempt to fuel Tory divisions over Europe. A Tory official said Mr Hague was "quite relaxed", but a party source said that Sir Alistair would be "deeply upset" at being vetoed.
Yesterday Mr Hague called for Mr Kinnock to lose his Brussels job as part of a "clean sweep" of the Brussels Commission after an inquiry published in March revealed sleaze and cronyism. The Government had been exploring the possibility of installing Mr Patten in another Euro-job, as "high representative" for foreign and security policy. But circumstances have conspired against that. The prospects of success were receding, with the German government making it plain that it is likely to have a candidate for the post, perhaps Gunther Verheugen, the Europe minister. And the post of commissioner has become more important in the wake of Mr Prodi's appointment.Reuse content