The forthcoming schools white paper is expected to encourage secondary schools to admit pupils in equal numbers from a range of ability bands.
Aides to Ruth Kelly, the Education Secretary, stress there is no question of compulsion and dismiss the notion that it would mean nationwide selection, amounting to the modern-day equivalent of the 11-plus.
But the idea, suggested in newspaper reports, has already taken hold among Labour traditionalists, creating ructions at Cabinet level over the plans.
Ability banding would have to be based on some kind of academic test at the end of primary. And for many in the Labour party, selection is a very dirty word.
"They just don't understand," say Ms Kelly's advisers, bemused that an attempt to create a classically comprehensive intake in schools is being interpreted in such a way.
But they acknowledge that the policy will prove hard to sell to the middle classes benefiting from current admission arrangements.
The right-wing press is already portraying it as social engineering that would mean such parents losing out against children from sink council estates in the scramble for the best schools.
But that will not put off Ms Kelly, who is determined to bring more social justice to the schools system. Speaking at a Training and Development Agency for Schools conference this week, she said she was working on "how we can get families living in council estates to exercise their choice in as powerful a way as those from privileged backgrounds".
To that end, the white paper is expected to introduce subsidised school transport for poorer families so that they too will have the means to travel miles across town in search of a better state school.
As The TES revealed last month, the Government also believes the kind of "choice advisers" used in the NHS could help by giving such families more information about admissions and the options open to them.
It would allow them to benefit in the same way as Prime Minister Tony Blair, who rejected his local Islington comprehensive in favour of the London Oratory in west London.
Ms Kelly will have to rule over a dispute between the Roman Catholic former grant-maintained school and parents from a nearby primary who say its interview-based admissions policy favours the articulate middle classes.
In a High Court case last year, the Oratory won the right to continue its policy of interviewing parents of prospective pupils.
Another strand of the white paper was highlighted this week when the Education Secretary revealed schools would be encouraged to "personalise"
pupils' education by setting classes by ability, where appropriate.
Between 2006 and 2008, the Government is to spend pound;335 million on tailoring learning for key stage 3 pupils and a further pound;60m on primary and secondary schools with high numbers of students falling behind.
Jo Boaler, of the school of education at Stanford university in northern California, argues that setting children by ability limits expectations, condemning poor pupils to a lifetime of underachievement.
Admissions Maze 19
LAW MAY NEED TO CHANGE TO INCREASE EQUITY
* Banding on the basis of three ability ranges was used by the Inner London Education Authority, abolished in April 1990, and survives in the boroughs of Greenwich, Lewisham and Tower Hamlets.
* The Specialist Schools and Academies Trust, representing more than 80 per cent of secondaries, highlighted banding in new admissions advice last month. Sir Cyril Taylor, the trust's chairman, thinks there may need to be a change in legislation to allow schools to band according to the ability range across a local area, rather than their actual applicants, if banding is to bring greater equity.
* Ruth Kelly's aides believe banding will be much more effective if groups of local schools decide to adopt a joint scheme. They think the local authorities could have a role in brokering this process.