The Conservative flagship education policy to turn all state schools into academies faces a £1.1 billion funding shortfall, as signs of a growing revolt emerge within the party.

George Osborne unveiled plans to turn 16,800 state schools into academies in his Budget last month. Those who have not been converted must have plans in place to do so by 2022.

But figures obtained by Labour from a parliamentary question suggest each transformation from school to academy costs £66,000 on average. It added that councils would have to cover a further £12,300 in costs, such as legal fees, per school.

The Government has dismissed accusations of a funding shortfall as “completely untrue”.

The “black hole” in funding comes as Graham Brady, chairman of the influential 1922 committee of Tory MPs in Westminster, told the Observer the plans could lead to the creation of “new and distant bureaucracies” rather than greater autonomy.

Mr Brady added he is writing to the Education Secretary Nicky Morgan to urge her not to rush the academy overhaul through Parliament, suggesting she could face a rebellion from her own colleagues.

Just last week the leaders of Conservative, Labour and Liberal Democrat parties, at a local government level, demanded the Department for Education drops the controversial policy. The council leaders said, in a joint letter, that there is “no evidence” to suggest academies perform better than council-maintained schools

Ms Morgan has insisted there will be no U-turn in the plans, despite considerable cross-party opposition.

Shadow Education Secretary Lucy Powell said the added cost came at a time when schools were facing "huge challenges", including reduced budgets.

"This costly reorganisation of our schools is an unnecessary and unfounded distraction, which could harm standards in our schools," she said.

A Department for Education spokeswoman said funding earmarked in November's Spending Review and the March Budget would be enough to support a "high-quality, fully-academised school system".

"We have over £500 million available in this parliament to build capacity in the system - including recruiting excellent sponsors and encouraging the development of strong multi-academy trusts," they told The Independent.

It also emerged teachers may take joint action with the junior doctors as part of their campaign against the Government, National Union of Teachers general secretary Christine Blower said.