Britain's top independent schools should seek big businesses prepared to fund free sixth-form places for talented state school pupils, the chair of the Headmasters' and Headmistresses' Conference (HMC) has said.
David Levin, headmaster of City of London School for Boys, will next week call on the organisation's 250-strong membership to woo companies to fund bursaries for languages, science and maths.
The places would be for pupils who otherwise may not have the chance to learn subjects such as physics or Mandarin at A-level.
Mr Levin, who for 10 years has raised cash in the Square Mile for his own school's bursary programme, rejected claims that such schemes amount to private schools "creaming off" the best pupils.
He stressed that many students would come from schools without sixth forms, and bursary programmes would be supported by outreach work in Years 10 and 11, so all would benefit.
His campaign, launched at the HMC's annual conference in London next week, comes as the country struggles out of recession, facing massive public sector spending cuts.
Mr Levin, whose school has means-tested bursaries funded by big-hitters such as HSBC Bank, Mann Group and two hedge funds, said: "The recession won't help, but you can have a go. We are hoping we can reach out for mutual benefit.
"We have consulted widely among our schools and the will is there. We want to build up a critical mass.
"If 200 schools took part and got funding for five bursaries, that would be 1,000 extra children who wouldn't have been able to do strategic, important and vulnerable subjects at university.
"Some prestigious universities have no choice but to take independent school pupils in some subjects because there aren't enough coming up from state schools."
The campaign has been given a cautious welcome.
Sir John Holman, director of the National Science Learning Centre, said he would welcome the scheme if it targeted poorer pupils.
He told The TES: "There's no doubt that some independent schools have highly qualified teachers who teach science and languages wonderfully well.
"I'd be in favour of such a scheme if it identified talented students who are genuinely deprived, but experience shows it is not usually such students who come forward."
He added that he would prefer donors to target deprived schools directly, with additional training for teachers.
Mr Levin's campaign comes as a consortium of 21 London independent schools reported record levels of interest in their existing means-tested bursaries after a #163;100,000 advertising campaign to promote them this September.
A website set up to deal with queries received 16,000 hits in just two weeks, far more than during the previous two years of the campaign.
Mr Levin, who was previously head of the state-maintained Royal Grammar School, High Wycombe, said that schools were now succeeding in increasing the take-up of bursaries, and stringent means tests, including visits to pupils' homes, meant the system was not being exploited by wealthy families.
The pressure for private schools to provide more bursaries has become acute since the Charity Commission warned schools they could lose their charitable status if they did not provide enough.
Although the commission is now indicating that other forms of contribution to the public benefit will be accepted, many public schools are still keen to demonstrate their willingness to comply.
Major private schools with large endowment funds do not stuggle to provide bursaries, but small schools and preps have found it difficult.
The issue is expected to remain a hot topic at next week's HMC conference, which will be addressed by Education Secretary Michael Gove.
David Levin CV
1949: Born Durban, South Africa
Educated in: Natal, South Africa.
1967-68: American field service scholarship, California
1973-74: MA, Sussex University
1974-75: Assistant master, Whitgift School, Croydon
1978-80: Assistant master, economics, Portsmouth Grammar
1980-93: Head of economics, then second master, Cheltenham College
1993-99: Headmaster, Royal Grammar School, High Wycombe
1999: Headmaster, City of London School.