When the Department for Education and Employment launched its new circular on selection, the initial response in the media was to say this was the policy that would put “clear blue water” between the two major political parties.

There is an assumption that if one talks about “selection” of 10 or 15 per cent of an intake to a secondary school, as the circular does, that this somehow has a connection, at least ideologically, with selection in its old-fashioned meaning - a system under which the most able children were chosen for grammar schools.

I read the circular with interest because that is not necessarily what selection means. In Hammersmith and Fulham we are undertaking a public consultation exercise through which we are discussing with our schools and parents the complicated notion of “selection for a balanced intake”.

This has involved introducing a baseline test at 11 which can be used for two purposes. It will be a measure of value added at 16-plus against the ability of the cohort when it enters the school at 11. It will also be used as a way of ensuring that our secondary schools, which are all committed to being comprehensives, achieve a truly comprehensive intake, as near as possible balanced with 25 per cent of children of above average ability, 50 per cent who are average and 25 per cent who are below average.

So, if a balanced intake involves getting 25 per cent of children of above average ability, of what significance is 10 or 15 per cent?

Furthermore, the problem of “unbalanced” intakes is usually associated with under-subscribed schools. If a school does not attract sufficient numbers to reach its standard intake, it is irrelevant whether there is an admissions policy to select 10, 15 or indeed 25 per cent by ability. In practice and in law, such a school has to take every child who applies to it.

Experience shows that this is likely to result in a skewing of the intake towards the average and below average pupils. Indeed, even if such a school did take 10 per cent of above average ability children, it could still be possible that the overall intake was skewed towards the below average.

A recent Sunday Times article implied that Archbishop Tenison’s School in Lambeth had transformed its unbalanced intake to a balanced one by selecting 10 per cent of its pupils by ability.

I would suggest that whatever else brought about that change, it was not simply selecting 10 per cent of it pupils by ability. It could do that and still remain under-subscribed with an unbalanced intake.

Psychologically, and in public relations terms, just using the words “selection” and “ability” may have given the impression the school was “selective” in the old fashioned sense, and thus in itself boosted the subscription to the school.

Cast your mind back to pre-open enrolment, pre-Greenwich judgment and pre-market forces and competition between schools. LEAs were concerned then to avoid the creation of “sink” schools with few able children and an ability profile skewed towards the bottom end.

One way of doing this was to allocate schools a certain number of places for each ability group. You did not fill your above average places with children from another band, even if it was over-subscribed. Isn’t this the position that the Government is trying to recreate through its circular, while claiming that somehow this has something to do with a “return to selection”?

In fact, it could be seen as a return to trying to establish comprehensives with a full spread of ability, which is exactly what the recent Opposition papers on education have been advocating.

The sting in the tail of the new draft circular and the real issue around which there will not be consensus, is not whether the 10 or 15 per cent are to be selected by ability. It is the change that allows over-subscribed schools to decide which pupils it takes after interviewing them with their parents.

This is social selection and moves away from the objectivity of criteria that the current circular 693 requires. It will be possible to be a comprehensive with an intake balanced by ability which has, however, weeded out any childfamily that the school considers might be “problematic” or a drain on its resources.

Christine Whatford is vice-chair of the Standing Conference of Chief Education Officers and director of education for Hammersmith and Fulham