Leading article: Of courage and credibility

Labour's leadership contest has taken time to come alive and only does so now as an awkward, closely fought duel between two brothers. Even so, the largely subdued campaign could prove to be an important one. As the main opposition in a hung parliament, Labour still has more to play for than seemed likely in advance of the general election. In theory, at least, their next leader has a better chance of being a Prime Minister than the victors of Conservative leadership contests in 1997 and 2001, when the winners faced landslide governments ruling in a relatively benign economic climate.

The Labour Party also has cause to feel relieved that the campaign is not a disastrous civil war, as some predicted it would be in the aftermath of defeat. There is, though, a significant downside to a contest without great ideological conflict, but marked instead by what Ed Balls described yesterday as the Miliband soap opera. None of the candidates is impressive enough as a public performer for one to have emerged as an overwhelming favourite, and all have failed to convey the epic nature of the task ahead. Labour is in a position to secure power again but only if it rebuilds a wide coalition of support. As David Miliband has dared to point out in his speeches, the party won less than 30 per cent of the vote at the last general election: hardly an endorsement. Labour is also susceptible to claims from the Conservatives and Liberal Democrats for some time to come that the seeds of Britain's economic fragility were sown during its long period in power. A new leader must address these challenges and others while facing David Cameron, a formidable political opponent more at ease with power than Gordon Brown or even Tony Blair.

Mr Cameron's relative calm is partly because the Coalition has roamed in a clear political field since the general election, taking considerable risks on the unchallenged terrain. It is in Britain's interests, as well as Labour's, that the party's next leader is capable of holding the Government to account, not least in relation to its policies for the economy.

Early on, Labour indicated that it wanted to choose between the two Miliband brothers. Of the other candidates, only Ed Balls has made a mark as the most effective critic of the Government, but his campaign has failed to gain internal support. David and Ed secured most nominations from MPs and trade unions – and nearly all the outgoing cabinet ministers declared in favour of one or the other. Ed has articulated views that, in key areas, chime with those of The Independent. He has acknowledged Iraq was a calamitous error, that the Government made significant mistakes in relation to civil liberties and in applying a light regulatory touch to the banks. He seems the most alert to a changing political culture in which a progressive alternative to the Coalition might involve reaching out to disaffected Liberal Democrats and smaller parties such as the Greens.

Yet in distancing himself from the last Government and the manifesto that he wrote, he has appeared at times too eager to address the party's core supporters in a contest that provided an opportunity for a wider engagement. He has also shown an unsure touch in his approach to the Liberal Democrats, seemingly calling for the party to be wiped out and then expressing a willingness to work with them, but not their leader. Perhaps inexperience is the cause. Ed Miliband was elected to the Commons only in 2005.

David Miliband has stressed repeatedly that Labour must appeal beyond the core vote if it has any chance of being a credible challenger at the election. In making this point he has not stayed in what his brother describes as a New Labour "comfort zone". If he had done so, he would deserve to lose. It was the New Labour comfort zone that Mr Blair occupied when he meekly allied Britain to the US in the invasion of Iraq. Mr Blair's subsequent populist authoritarianism in relation to civil liberties was also part of his comfort zone.

But David is more than a Blairite echo and has openly acknowledged mistakes made by Mr Blair as well as Mr Brown. As Environment Secretary he devised policies in relation to climate change that were more daring than those being formulated by the Coalition. His record was less impressive in the Foreign Office and he is damaged by his refusal to be more critical publicly of Mr Blair's naively reckless adventurism.

Yet his three years as Foreign Secretary gives him the credibility to become an alternative Prime Minister. Internationally he has a voice and, importantly, it is a pro-European one. David was respected enough to be offered the foreign affairs brief for the European Union last year, a post he turned down in order to stand for the leadership now, a sign that he also possesses a steely ambition that goes beyond his caricature as a well-meaning geek.

Both brothers have expressed a readiness to understand the failings of New Labour. Ed has done so more explicitly. The winner must act on the easy generalisations of a contest and move the party away from an authoritarian, tribal populism that has alienated a significant section of potential support. The test for one of the Milibands is still to come.