Leading article: A new-look Opposition that must show itself worthy of the name

There is much that is positive about the new Shadow Cabinet, and Ed Miliband deserves credit for the dispatch with which he made some hard decisions.

The election for membership inevitably places constraints on the leader's choice, and the results of this particular election only compounded them. But this is a team with a genuinely fresh look; Brownite and Blairite shadows have largely been banished. There are more women in senior posts, and Sadiq Khan, the up-and-coming Muslim MP, becomes shadow Justice Secretary.

The most crucial decision, however, concerned the post of shadow Chancellor, both because there was one obvious, but contentious, candidate and because the economy is where the key battles will be fought in coming months. In appointing Alan Johnson, Mr Miliband avoided two obvious pitfalls. Ed Balls, who made little secret of his ambitions in that direction, would have been vulnerable to taunts about his association with the last government, with Gordon Brown personally, and with the financial crisis (whichever fitted best the point in hand). But to appoint his wife, Yvette Cooper, to the post would have risked perpetual speculation about a new "psychodrama" of the sort the party is only emerging from after the Miliband duel.

As a minister, Mr Johnson was adept at shutting down controversy (and bad headlines) in the successive departments he ran. He also inspired confidence as a Commons performer. The prospect of the working-class boy made good – an image he has cultivated – parrying George Osborne, ex-public school and Bullingdon Club, offers a tantalising study in contrasts. How the stolid, reliable Mr Johnson will acquit himself against the politically nimble and fluent Mr Osborne, however, is a question that awaits its answer.

Mr Balls, who came third in the poll, and Ms Cooper, who easily topped it, have each been allocated a great office of state, while being placed conceptually as far as possible away from each other. He is shadowing the Home Secretary, she the Foreign Secretary. Thus Mr Miliband also avoided the "cat-fight" accusations that might have come his way had he appointed Ms Cooper to shadow Theresa May, but it must be asked whether foreign affairs necessarily plays to her particular strengths.

As shadow Home Secretary, Mr Balls will find himself up against Ms May on combating crime and police reform, but also on immigration. During the Labour leadership campaign, he criticised Gordon Brown for not restricting arrivals from the new EU states. Even if migration is an unpopular cause, however, the party should not leave it to the Liberal Democrats to defend migrants' rights. Mr Balls must negotiate tricky territory.

The gauge of how good a job Mr Miliband has done in forming his team, however, will be how effectively it manages to oppose, collectively and individually, a Coalition that has grown in confidence. Labour did better than might have been expected during its leadership interregnum, partly because ministers were shadowing their own former portfolios. Now, all new to their jobs, they must challenge ministers who have a head start. This will not be easy, but with the results of the Comprehensive Spending Review to be announced in 10 days' time, the country is already crying out for a strong opposition.