Top comprehensives are overwhelmingly opposed to Government proposals for increasing schools' freedom to select pupils.
Last week's announcement by Education and Employment Secretary Gillian Shephard of a White Paper encouraging increased selection was condemned by headteachers at non-selective secondaries in England. The schools were rated outstanding in the Office for Standards in Education's annual report.
Privately civil servants and senior figures within the grant-maintained sector believe the scheme has limited appeal and at most, schools will select up to 30 per cent of pupils.
The headteachers described the plan as "specious nonsense", "fundamentally mistaken" and "completely retrograde".
David Chamberlin, head at Arden School, Solihull, where 77 per cent of pupils achieved five or more A to C passes in last year's GCSEs, said: "We have no intention of increasing selection. You simply cannot have selective schools running alongside comprehensives. For the Government to talk about that as being an improvement in choice and diversity is specious nonsense.
"It's vital to embrace the whole ability range in your intake. If you just have a few schools creaming off the top pupils you will return to the bad old days and leave 70 per cent of children getting second best treatment. That would prevent us from attaining the training targets set by the Government. "
Mrs Shephard promised: "Where a school wants to introduce a greater degree of selection, because it believes it can provide a better education for its pupils by doing so, we want it to have that choice."
But George Pollard, headteacher of Thomas More RC High in Crewe, said: "This is a completely retrograde step, totally unnecessary in the context of raising standards. I've worked in the comprehensive system since 1960 and it's the best form of education we have. I don't understand why the Government is doing this in the name of standards. More grammar schools would mean a better chance for the few, but would cause the education of the vast majority to suffer. I think parents in Cheshire would say exactly the same thing."
John Wakely, principal of Ringmer Community College, East Sussex, said: "I believe the proposals are fundamentally mistaken. We should be committed to delivering the best possible education for all abilities. East Sussex has no grammar schools and I would expect the county to remain fully committed to the comprehensive system."
Most heads were confident that their views mirrored those of local colleagues, but some acknowledged that their anti-grammar stance would have to be reviewed if neighbouring schools went down the selective road.
At Copthall Girls' in Barnet, headteacher Sheila Walden said: "We are not looking at becoming a grammar. Whether or not we remain in that position will depend to a certain extent on what our neighbours do. Mill Hill County is now selecting 30 per cent of its pupils on academic ability and if that were repeated elsewhere and had a knock-on effect on our applications we might be forced to think about some kind of selection."
Jane de Swiet, headteacher at selective Henrietta Barnett in north London, where 864 girls applied for 93 places this year, said: "I think most comprehensives would prefer to be guaranteed a certain proportion of pupils from each ability group, rather than more powers of selection. We've often discussed in Barnet the danger of non-selective schools becoming like secondary moderns. You should make sure that schools have a top as well as a bottom. "
The Department for Education and Employment said the number of local authority schools applying for permission to select more than 10 per cent of pupils was still in single figures.