Ed Miliband: Challenges ahead for the new Labour leader
The Ed Miliband backlash began before he was even elected.
He was dubbed "Red Ed" by right-of-centre tabloids when it was revealed more trade union bosses backed him than any other candidate.
And the New Labour establishment are whispering that he could be another Neil Kinnock - doomed to be a great Labour opposition leader, but not trusted by voters to become prime minister.
Some have been more explicitly critical. Lord Mandelson said the election manifesto which Ed Miliband wrote failed to address the concerns of people who are not natural or "automatic" Labour voters. And even his own brother suggested the manifesto failed to inspire.
The extent of criticism which the younger Miliband has attracted from Labour's old guard has persuaded some of his most loyal followers he is now not beholden to anyone and has a free hand to reshape the party which he feels has been short of passion and purpose recently. Under his leadership, there will be no return, he says, to the "comfort zone" of New Labour. He is the changemaker.
But in truth, he may have to build alliances rather than let burning bridges collapse.
Although popular with party members and trade unionists, far more MPs backed his brother David.
So not only will he have to reunite his family, he will have to unite his party.
It is clearly going to be difficult for his big - and, until now, better-known brother to serve under him - David has said time and again if he had felt Ed would make a better leader he would have been running his campaign.
So he will need to be given - and persuaded to take - a top job that suits his status and he will have to find roles for some of David's prominent supporters.
David also brought in far more campaign funds from rich backers such as Lord Sainsbury and Ed will not want those cheques to stop just because he is now leader - even if he does successfully bring in far more small donations from re-enthused activists.
But when it comes to personnel, Ed does not entirely have a free hand.
The shadow cabinet is chosen by fellow MPs, not chosen by him. Nominations open on Sunday and the field is likely to be large.
The chief whip is elected separately so cannot be counted upon by the new leader to shepherd the votes of confirmed, or wannabe, Ed Milibandites towards the people he wants in his front rank.
So it is possible he will have less scope for reshaping the party than his current supporters think.
But he will have personnel headaches which go beyond what to do with his brother.
He will also have to decide what role to offer the other Ed - Mr Balls. They both worked for Gordon Brown and should be politically closer than the Miliband family itself.
But Ed Balls was seen as the more senior adviser, and it may ruffle feathers a little that their roles might appear reversed as MPs.
The veteran leftwinger Tony Benn used to say "it's policies not personalities" that matter but, of course, it is really both.
Even if Ed soothes the prickly politicians in Labour's ranks he will have to face up to serious policy challenges too.
He has been criticised for his Labour manifesto but privately he felt it was not radical enough and he had been too constrained by Peter Mandelson and Alistair Darling in particular. Free to express his own views during the leadership contest, he has been accused of lurching to the left.
It is an accusation his opponents in the coalition will continue to make. But he hopes that some of the apparent "left-wing" positions he has adopted will appeal to those Liberals uncomfortable with Nick Clegg's leadership and the coalition's cuts.
He believes his embrace of a graduate tax - as the price for scrapping tuition fees - and his calls for the future of Trident to be decided in the strategic defence review - will not only distance himself from the policies of the last Labour government, but help him harness support from so-called progressive voters - ie non-Conservatives - who did not back Gordon Brown at the election.
So, there is evidence of strategic thinking here. But there has been irritation at what some of his leadership opponents regarded as opportunistic tactics during the long contest.
Although a key government adviser at the time, he was able to use the fact that he was not an MP in 2003 to distance himself from the decision to go to war in Iraq. He has said he would have given the weapons inspectors more time.
Supporters of his brother were annoyed by this but so too was Ed Balls. He made it clear he would have voted for war but subsequently would have regretted it, and his backers believe Ed Miliband is trying to rewrite history.
But given the internal divisions in Labour over the war, Ed Miliband has been able to turn his lack of experience as an MP - he was elected in 2005 - to his advantage, arguing successfully that he was best placed to give the party a fresh start and allowing it to ditch some of the heavier baggage from the Blair/Brown era.
As for other apparently left-wing positions, some are more rhetorical than real - he campaigns for a living wage - higher than the minimum wage - but does not commit himself to legislation. His opposition to ID cards is shared by Messrs Cameron and Clegg. But while he has set out a range of policy positions over the past four months he will, in his first leader's speech this week, have to weave these into a coherent narrative.
And he will have to convince the wider public that he has something to say about their everyday lives and that his whole political offer is not confined to winning over disenchanted Lib Dems. So he will be challenged to say if he wants fewer cuts - which he does - what taxes would he put up?
He has already committed himself to keeping the 50p top rate but he may have to be more specific about what more he would raise from the banks, with all the attendant dangers of being portrayed as anti-business. And as he has not committed himself to cancelling all the cuts, the coalition will want to know he would save money as well as spend it.
But even bigger challenges lie ahead.
If trade unions which have helped fund his campaign do strike over jobs or pensions, how he reacts could define his leadership. But this week he will simply have to go on the front foot, demonstrate he is brimming with ideas to re-energise his party, and ensure that he does not give his opponents the opportunity to define his leadership for him.
And there is an early test he will have to pass. Without a permanent leader, Labour has recovered in the polls with some surveys putting the party neck and neck with the Conservatives. So he will have to do what he can to ensure that Labour does not become less popular now that it is no longer leaderless.