The last great divide between Conservative and Labour is whether secondary schools should take children from the neighbourhood or whether they should be allowed to select on the basis of aptitude or ability.
David Blunkett, Labour's education frontbencher, knows that the traps are being set and that the legislation will be used to focus attention on the apparent contradiction between Harriet Harman's choice of a selective school for her son and Labour's commitment to comprehensives. The expected charges of hypocrisy will not be deflected by any fudging on policy, he says.
"I am prepared to take this head-on. Labour is opposed to academic selection at 11 and we will operate sensible, open admission policies."
Fortunately, Mr Blunkett can already cite the problems besetting Bromley, where the decision by one school to apply for permission to introduce 25 per cent selection has led to the other comprehensives in the Greater London borough introducing 15 per cent selection.
"These sort of admission procedures are a problem for parents. It is creating an extra hoop for them to have to go through," he says.
However, while Labour is not in favour of selection, it remains unclear as to whether that means parents will have little choice other than their local comprehensive, whatever the standard of education on offer.
"I have never said parents have to send their child to the local school. There will be a degree of parental preference and we will want schools to play to their strengths," he says.
An incoming Labour government would, he says, take effective action to lever up standards in schools that are performing poorly. As an example, he quotes the school his own son attends in Sheffield, which, he says, has made great strides in pulling itself up.
It will not be easy to shrug off the Harriet Harman episode as one parent making an individual choice for her son. Tony Blair has admitted his most serious mistake since taking on the Labour leadership has been to underestimate the impact of her decision to send her son to a grant-maintained grammar school.
Grammar schools do have their advocates within the party. However, Mr Blair appears not to have been aware that most back-benchers are hostile. Not more than a handful of his MPs would sign up to a programme that includes selection, but such influential figures as Will Hutton, commentator and editor of the Observer, promote schemes that mean a return to grammars, possibly by expanding the number of state-funded places in independent schools.
As far as Mr Blunkett is concerned, such talk is confined to the supper parties of London's chattering classes and there is little prospect of Labour putting extra money into assisted places, when policy is to phase them out.
In the coming months, Mr Blunkett has the daunting task of responding to Eric Forth, one of the most effective Parliamentary performers, who will be leading for the Government during the passage of the Education Bill. At the same time, Labour will have to mount a campaign against nursery vouchers on the grounds that they will not create more places.
During the recess Mr Blunkett has been studying the under-five policy paper drafted by a sub-committee led by Margaret Hodge MP. The proposals are likely to be refined before being published later this year. Labour has the problem of making clear that, while it opposes vouchers, it has a more workable scheme for providing day care and education for pre-school children.
There are problems with the timing; vouchers are due to drop on to door mats only weeks before the most likely date of the next election. Local authorities are being invited to consider how a Labour government could quickly re-direct finance back to the local level.
A more immediate hurdle is Labour's annual conference in a couple of weeks. The preliminary agenda suggests that the activists have yet to come to terms with the policy that would allow GM schools to become foundation schools. As well as criticism of an unnamed leading member of the Labour front bench for her decision to send her son to a grammar school, there are a number of resolutions calling for GM schools to be returned to local authority control.
Last year, Mr Blunkett was able to win over the conference with a pledge that under a Labour government schools would not be able to select their pupils. That phrase has been used against him ever since.
Mr Blunkett has grand plans for the day he moves into Sanctuary Buildings. But before that he faces a long election campaign with the battle over education at its centre.