The sharp achievement gap between state and private school-educated pupils means there is a "shocking waste of potential", according to the chairman of educational charity the Sutton Trust.
Sir Peter Lampl's remarks come in the foreword to a new report that shows private school pupils will earn significantly more than their state school peers.
"This is a shocking waste of potential. This report clearly sets out the advantages that can be gained from a good private education," Sir Peter writes.
The Sutton Trust is calling for more independent schools to take on able pupils from less well-off backgrounds.
The charity suggests private schools should get the same funding per pupil as state schools, with the ability to charges fees on a means-tested basis, with the poorest paying nothing.
Their study suggests extending such a scheme to 100 leading private schools would cost the Government about £215 million a year.
More top news
Business Secretary Vince Cable says the party plans to double the number of employers offering apprenticeships to young people.
A study suggests people who are obese fall into six types including heavy drinking males, young healthy females and those in poorest health.
Ed Miliband will announce the plan to crack down on exploitation which he says is driving immigration of low skilled workers and poor wages.