Does it really matter whether it’s Buggins or Muggins who becomes a secretary of state? Most ministers see their footprints in the Whitehall sands soon blown away. A few, however, do make a difference; their departments are more than a staging post on the way to the top or to the knacker’s yard. Aneurin Bevan is remembered as the architect of the National Health Service. Nigel Lawson and Michael Heseltine had the self-confidence and energy to get things done under Margaret Thatcher, the former by removing the dead hand of the state, the latter by imposing it through creative planning.

Britain cries out for a great education secretary. Someone has to repair the damage done by Tony Crosland, the destroyer of our elite but narrowly based state grammar schools, who gave us what Alastair Campbell – in a rare moment of candour – called “the bog-standard comprehensive”.

Into what category of minister does Ed Balls, the schools secretary, fit? He has the right intellectual qualifications for the job. At Oxford he obtained the fourth best politics, philosophy and economics degree in the university – ahead of the young David Cameron.

As adviser to Gordon Brown in opposition, he dug his boss out of a terrible hole: the shadow chancellor’s enthusiasm for the Conservative government’s fixed exchange-rate alignment with European currencies, the ERM, which became a respectable but personally damaging error when Britain crashed out in ignominy. Balls is credited with devising the alternative framework, an independent Bank of England.

Brown’s lieutenant has sharp political judgment, too. Balls urged his boss to capitalise on a good start as PM by going early to the country for a personal mandate – Brown’s best and perhaps only chance of winning an election outright. Balls also helped to stall the feint at power by David Miliband, the foreign secretary, last autumn by inserting the potent “no time for a novice” line in the leader’s Labour conference speech.

As a reward for playing Robin to Gordon’s Batman, Ed got a big supply ministry, education, and promptly made it bigger by grabbing responsibility for children’s welfare and social services. If he fails it won’t be for lack of resources: spending per pupil has gone up by 55% in real terms since 1997; there are 35,000 more teachers and a vast new army of 172,000 teaching assistants. Salaries are up, information technology has been installed and new schools have been built.

Yet look at the scale of the challenge.

Private schools (7% of children) had more pupils gain three grade As at A-level last summer than all the comprehensives put together. Poorer students are falling further behind their middle-class contemporaries. A good state system should be an engine of social mobility. In the past, Ken Baker for the Tories and David Blunkett and Lord Adonis for Labour really tried to turn the tide, but it needs constant effort.

This battleground matters. The Conservatives may win the election on weariness with Labour as much as any enthusiasm for the change they represent. But the opposition really does have a reforming agenda. It proposes to build on Tony Blair’s belated public service reform programme, especially his plans to provide more variety and excellence in state schools, of which the city academies are a shining example. Parents, charities and private companies will also be encouraged to set up their own schools under the state’s umbrella.

Heading the Tory charge is Michael Gove, a worthy antagonist for Balls. The former radio and print journalist is a romantic, a Scottish unionist who shares the American dream of making the world safe for democracy. He is no Tory toff, despite his Oxford Union president’s debating style and his Notting Hillbilly friends.

As a new MP, Gove volunteered to become a spear carrier for Cameron when the future leader took the education brief. Smart move. Now entrusted with Cameron’s former job, Gove is committed for the long haul: his ambition is to make an indelible mark on our education system in government.

No one doubts Ed’s ambition either. Some thought his new ministry was but a stepping stone back to the Treasury, this time as chancellor and heir to Brown. The young Hugh Gaitskell, remember, vaulted to the Labour leadership, having been promoted to No 11 at the fagend of the Attlee government. But the recession has put thoughts of a change at the top out of fashion. For all the talk of tensions between No 10 and No 11, Alistair Darling’s removal at this stage could undermine confidence in Brown as much as the economy.

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