Labour's attack on private schools would be used to fund incentive payments to stop teachers leaving the profession, the party revealed yesterday.
But the policy was last night in disarray after it emerged the money has already been allocated elsewhere.
Sir Keir Starmer has vowed to retain predecessor Jeremy Corbyn's policy of stripping private schools of charitable status, meaning VAT would apply to fees.
The Conservatives pointed out the proposed £1.7billion to be raised from the contentious move was allocated by Labour in January to pay for 6,500 more teachers and support staff.
A Tory source said: 'They've now pledged two different policies with the same money.'
Former Downing Street education advisor Chris McGovern, chairman of the Campaign for Real Education, said: 'It suggests Labour need to go back to school themselves because they can't do their sums. It's obviously a policy of chaos.
'Actually, the imposition of VAT on school fees is going to increase the number of children in state schools so any gain will be offset by the extra cost to the sector. The state would be likely to face extra expense.
