Already the Conservatives have attempted to portray the result as a triumph for the trade unions and a lurch to the left by Labour. Mr Miliband finds himself being branded as ‘Red Ed’. But for someone who served his political apprenticeship as one of Gordon Brown’s advisers, before being elected as an MP under Tony Blair and appointed to cabinet by Brown, this seems a bit odd. These were hardly revolutionary left-wing politicians.

Certainly, Miliband has said little that suggests he plans a return to penal tax rates and re-nationalising British industry – policies that Labour tried in the 1970s and 80s. He separated himself from the other mainstream candidates by stating that he had opposed the Iraq war – hardly a radical statement since many Labour MPs, even those who ended up voting to back the invasion, had serious misgivings. Meanwhile, he has said that the British economy needs to be rebalanced, with less focus on the financial sector, a higher levy to be paid by the banks, and a more gradual move to fiscal consolidation. The Conservative-led coalition has promised deep public spending cuts to balance Britain’s 10% budget deficit, but the ongoing disaster in Ireland and other European countries shows the dangers of returning to recession if you cut too early and too deep.

There is no denying the fact that the trade unions, still a significant force in British labour politics, are happy. While Ed Miliband polled fewer votes among MPs, MEPs and party members than David, he won 60% of the trade union vote, enough to give him his victory. This may give the Conservatives a little ammunition, but it should also restore some money to Labour’s depleted coffers. After the election, when it was easily outspent by the Conservatives, Labour is more than £20m in debt. The big unions will be expected to dig into their pockets to provide a down payment on this debt.

The truth is that Ed Miliband is, at 38, young and less well known than Labour’s old guard who served under Blair and Brown. So he will have to do as David Cameron did in 2005 and hit the ground running. But we should not forget that David Cameron only became an MP in 2001 and, before becoming Prime Minister, had never served as a government minister. Ed Miliband has nearly three years of cabinet experience. Youth is what you make of it – it is neither a virtue nor a vice.

Another old political saying is that ‘opposition parties don’t win elections, governments lose them’. Just months after it polled 29%, Labour is now neck and neck with the Conservatives on between 35 and 40% in the opinion polls. If the coalition does not have the British economy booming within five years, then life will be quite easy for Ed Miliband. If the economy stagnates and unemployment soars, then he, and his party, will have been proven right, and the coalition will probably be finished.

Miliband’s first priority must be to make sure he has a united party behind him. The narrowness of the victory – 50.65% to his brother’s 49.35% – stunned many. Ed Miliband must make sure that he offers the olive branch to his brother’s supporters and campaign team. The result must have been a devastating personal defeat for David Miliband, and he has behaved with enormous dignity. I hope that we will not lose him from European public life for good. Having turned down the opportunity to become EU High Representative on Foreign Affairs to try to help his own party, David Miliband has paid a high price. I hope – and believe – that we will see him back in frontline politics soon.

But now is Ed’s moment. He should be able to rebuff the ‘red Ed’ name easily by offering a sensible deficit reduction plan that is balanced between mild spending cuts and tax rises, and by changing the mentality of his party from a top-down leadership-dominated structure to a more grassroots-oriented party that takes account of the views of ordinary party members. In the 24 hours after Ed Miliband was elected over 1,000 new members joined the Labour party. I would say that’s a pretty good start on the road back to power.