Mr Howard said grammar schools were being attacked 'by stealth'

He said the "pursuit of excellence in all its forms" was a key component of his educational policy.

Under this system, England's 164 grammars would "flourish", Mr Howard told a meeting of the National Grammar Schools Association in London.

He said he would announce detailed policies within the next few weeks.

'Quality first'

Mr Howard told delegates at the RAF Club in Mayfair: "Never again should a politician, driven by ideology, be able to wipe out an entire school structure.

"Schools should succeed and fail on one basis alone: the quality of the education that they give our children."

Mr Howard said the Labour government had "sought to abolish grammar schools by stealth" since being elected in 1997.

He criticised legislation which allows parents to hold ballots on the future of grammar schools in their area.

Mr Howard added: "The pursuit of excellence in all its forms - academic, vocational, sporting, musical, charitable - should be the aim of every part of our education system.

"Few can excel at everything, but no-one should be condemned to an expectation of mediocrity or underperformance across the board."

Everywhere they look, grammar school heads see someone against them Brian Wills-Pope, National Grammar Schools Association

The Tory leader, himself a former grammar school pupil, said mixed-ability teaching "should be the exception, not the norm, in classroom teaching".

In future, parental choice would be the "overriding factor" in keeping a school open.

This would be achieved, he said, by allowing successful ones to expand and even take over neighbouring schools.

Mr Howard told the meeting: "With your track record, you will not only survive, you will flourish.

"You will be able to take over less successful schools, if it becomes clear that there is pent-up demand for your services. You will be able to raise money for expansion and attract as many pupils as you see fit."

One audience member asked Mr Howard if his plans included restarting "grant-maintained" schools, done away with by the Labour government.

'radical plans'

These received money direct from central government, rather than via local authorities.

Mr Howard said his proposals, to be announced in a fortnight, would go "beyond that".

He also asked head teachers to send him their suggestions about how to run schools.

Opponents of grammars, which exist only in a few areas of England such as Kent and Buckinghamshire, and across Northern Ireland, say they are elitist, as they choose the brightest pupils by exam at the age of 11.

Responding to Mr Howard's speech, the National Grammar Schools Association's chairman, Brian Wills-Pope said: "It gives us hope. We are running some of the best schools in the country and we have taken a battering since 1997.

"Everywhere they look, grammar school heads see someone against them. The worst part is that they are actually doing a good job."