Let no one say that Gordon Brown can no longer spring a surprise. His recall from exile in Brussels of Peter Mandelson – twice sacked ignominiously from the cabinet, and the closest ally of Mr Brown’s arch-rival Tony Blair – bids fair to be one of the most startling comebacks since Lazarus. For a sinking prime minister, it is a gamble of astonishing audacity.

From Mr Brown’s point of view, recruiting Mr Mandelson adds heft to a colourless cabinet not overburdened with talent. It will wrongfoot rivals plotting to topple the prime minister, while the tactical acumen of New Labour’s former spin-doctor and campaign chief may even help Mr Brown forge a workable strategy to take the fight back to the Tories before the next general election.