Bobby's back. As a piece of political theatre, the return of Peter Mandelson, the man who styled himself as the backroom �Bobby Kennedy� to Tony Blair�s Jack, knocks the whole elaborate staging of the conference season into a cocked hat.

Bobby's back. As a piece of political theatre, the return of Peter Mandelson, the man who styled himself as the backroom "Bobby Kennedy" to Tony Blair's Jack, knocks the whole elaborate staging of the conference season into a cocked hat.

The EU Trade Commissioner's elevation to the House of Lords - arise Baron Mandelson of Hartlepool? - is one of these rare moments, a genuine political shocker.

This is the comeback of the political era, a turn that will only be matched if he actually helps Gordon Brown win a fourth term for Labour.

An architect of New Labour, the spinning Prince of Darkness, Mandelson has had to twice resign from the Cabinet in controversial circumstances. More astonishing than his rise from the dead for the third time is that he has come to help the man who many still regard as his sworn enemy, a man who was the opposite side of a rift that ran through new Labour for more than a decade.

Gordon Brown's contempt for Peter Mandelson is the stuff of Westminster legend.

Mr Brown regarded him as a traitor since the day of John Smith's death when Mandelson threw his lot in with Tony Blair's leadership bid. It was the right call, as it turned out, but the well of friendship was forever poisoned.

Although Mandelson and Brown played a triangular role around Tony Blair in building New Labour, completing a renewal started by Neil Kinnock and bending the media to their message, the Hartlepool MP was cast into outer darkness by the new Chancellor.

Mandelson and Brown were once described as like "scorpions in a bottle", and only one of them would crawl out alive. Mandelson's reputation as the master of spin was not helped by his appointment in 1997 to the job of minister without portfolio - a trouble-shooting role with special responsibility for the Millennium Dome.

Before the dome was opened, Mandelson was made trade secretary but lasted just five months before he was forced to quit in December, 1998, over a secret £373,000 home loan he accepted from the then paymaster general, Geoffrey Robinson.

Although his vanity, and his desire to keep up with his wealthy friends in the London elite, let him down, Mandelson bounced back.

Westminster was shocked when he made a spectacular return to the Cabinet as Northern Ireland secretary in 1999, only to quit again in 2001 after being accused of helping one of the Hinduja brothers get a British passport in return for a £1m donation to the dome.

Mandelson was cleared by an inquiry of any impropriety but Blair and Alastair Campbell, panicked by the "Peter again" headlines, cut the cords.

Vindicated, but with his reputation tarnished, Mandelson hit back at his critics on the night of the 2001 election. They had predicted his demise but in an unusually impassioned statement, he declared: "I am a fighter, not a quitter." Soon, though, he was on what many regarded as a ticket to oblivion as Britain's nominee for EU Commissioner. But it was a role in which he excelled. In fact, he is well regarded by officials and politicians in all the posts he has held.

Mr Mandelson has enemies, in politics and the press, and for a while it was seen as sport to go baiting the minister. He will be a target from day one; Sunday journalists will be checking his EU pension entitlements right now.

He is a risk, and a divisive figure, but the return of Mandelson will electrify politics and enliven the Brown government. The detente between the two men, Mandelson was always needy of Mr Brown's approval, came in phone calls over the last few months.

He brings unrivalled experience of world trade matters which will bolster Mr Brown's response to the economic crisis, and he has the strategic thinking that can win by-elections and general elections.

The other advantage of taking aboard a pilot that could steer his battered ship though the Corryvreckan whirlpool is that Mr Brown now binds the Blairites to the mast of his government.

Outside Downing Street yesterday, Mr Mandelson said he had not been seeking office and was not expecting it. The smile said more - he is back.