The shadow chancellor is to throw his weight behind an “Abolish Eton” debate at the Labour party conference this weekend, as he declares that “private schools don’t need to exist” in an equal society.

John McDonnell said he supported a motion put forward by the campaign group Labour Against Private Schools calling for independent schools in England to be stripped of their charitable status, to have limits placed on their pupils’ entry to universities, and for their assets to be used by the state education sector.

“We know that our society is grotesquely unequal, and part of the reason for that is because of the inequalities in education, particularly in private schools, where large amounts of money are spent on a privileged few,” McDonnell said.

Abolish Eton: Labour groups aim to strip elite schools of privileges Read more

“That’s why I support the campaign now for us to talk about how we ensure an integrated education system, where private schools don’t need to exist and should not exist where we have equality of education.”

Holly Rigby, a state school teacher and one of the organisers of the motion, said the campaign was delighted to have McDonnell’s support. “This is an historic opportunity to dismantle the private school system that confers unfair privileges and perpetuates inequality,” she said.

The campaign, which uses the Twitter handle @AbolishEton, has received a surge of support since its launch two months ago, including public backing from the Labour party chair, Ian Lavery, and the party’s former leader Ed Miliband.

“I hope this campaign will pick up support and eventually become Labour party policy,” McDonnell said. “I think we can gain a large number of votes on this issue, because I believe people think that everyone should have a fair start in life, and that starts by making sure that we all have the same access to education facilities.”

Play Video 7:03 Should we abolish private schools? – video

The motion is likely to be debated at the party conference in Brighton on Sunday, if it survives the selection procedures. It calls for an election commitment to “integrate all private schools into the state sector”, including withdrawal of their charitable status. It also wants to limit university admissions for private school students to the same proportion as that of the wider population.

Last week the Daily Telegraph reported that Labour was looking at ending discounted business rates for independent schools, as well as imposing VAT on independent school fees, a policy Labour previously adopted in its 2017 election manifesto. According to a leaked document it estimated that applying VAT to school fees alone would raise about £1.6bn.

Mike Buchanan, the executive director of the Headmasters’ and Headmistresses’ Conference (HMC), which represents the most prominent independent schools, said any proposals to abolish private schools “would tear apart the fabric of education” in the UK.

“Independent schools have played a vital role in the education system for generations and they are recognised around the world as beacons of excellence. We want to see all pupils getting the same opportunities by pushing up standards everywhere, not by destroying some of the best,” he said.