Editorial: Time for Mr Miliband to fill in some of the blanks

Labour has passed the early tests. Now it must prove itself a credible alternative

The Labour Party begins its conference in Manchester this weekend in better shape than most pundits – and some of its leading figures – had assumed would be possible after the trauma of defeat two years ago. In fact, most polls suggest a double-digit lead over the Conservatives, more than enough to secure a sizeable overall majority at the next election.

On some levels, at least, such a lead is well deserved. Labour has shown a surprising degree of discipline and unity, confounding expectations of a lapse into near civil war after the 2010 election. And at last year's conference, Ed Miliband stole a march in the important battle of ideas by focusing on "responsible capitalism", a theme perhaps even more relevant now than when he first spoke of it. His shadow Chancellor, Ed Balls, also claims some vindication – justified or not – for his warnings that the Coalition's stringent economic policies risked a second recession.

Look behind the headline figures, however, and the polls suggest the lead over the Tories is largely down to an anti-Coalition mood, rather than an actively pro-Labour one. Indeed, there is not yet much evidence of great enthusiasm for Mr Miliband's party. And even the double-dip recession that partly explains Labour's current popularity is a potential trap.

Not only is it probable that the economy will be growing again by the time of the election, taking some of the sting out of the current anger at the Coalition; more immediately, the economic gloom has narrowed the differences between Labour and the Coalition. In a pre-conference interview with this newspaper, Mr Balls insisted, with good cause, that he cannot allow shadow cabinet colleagues to pledge future spending increases, given the uncertainties over the economy. How, then, would Labour differ from the Coalition, if both sides are similarly constrained?

While Mr Miliband and Mr Balls are right to argue that it is too early to spell out their precise tax and spend policies for the 2015 election, they do need to provide a few more details. Without them, slightly contradictory messages fill the vacuum: the deputy leader, Harriet Harman, has suggested that Labour will not be tied to the Coalition's spending plans at the next election, even as Mr Balls is ruling nothing out.

The need for more detail also applies to Mr Miliband's vague advocacy of a more responsible capitalism. Amid the general rhetoric, there is little sense of how such responsibility might be brought about, or what he envisages the government's role to be. In fairness, these are complex questions with no easy answers. But if Mr Miliband is to live up to the credit he has accrued for asking them, then he must now start to sketch out some answers. And the same might be said of his concept of "predistribution" – a characteristically inaccessible term crying out for policies that voters can understand.

More than anything else, Mr Miliband must start to tackle the continuing uncertainty about his leadership. In many ways, he has been bold and astute in his chosen themes; at Prime Minister's Questions, he is often effective, and, so far at least, he has shown a steely calm when under fire. But his personal ratings remain well below those of his party, and, in an increasingly presidential culture, voters still struggle to see him as a prime minister. For the next few days, he has the political stage largely to himself. He must use the opportunity.

It is Labour's good fortune to be the only real option for voters disillusioned with the two parties of the Coalition. But with such luck comes increased scrutiny. Labour has passed some of the early tests of opposition. Now Mr Miliband and his colleagues must meet the much bigger challenge of becoming a credible alternative government.