Controversial plans to make every school an academy ran into more political problems today, with Labour claiming it faces a £1 billion funding shortfall and a prominent Conservative backbench MP raising serious concerns over the scheme.

Figures obtained by Labour from a parliamentary question show that, to date, the cost of converting to academy status has been an average £66,000 per school.

On this basis, the opposition says the bill for the Government’s plan to turn England’s remaining 16,800 maintained schools into academies by 2022 will be £1.1 billion.

The Department for Education has pointed to “over £500 million available in this parliament to build capacity in the system”.

But George Osborne’s budget last month appears to suggest that most of the extra £640 million for education will be used to introduce a new school funding formula. Labour says this will leave just £140 million for academy conversion costs.

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.

Meanwhile Graham Brady, chairman of the influential Conservative backbench 1922 committee, has voiced his concerns about the academisation plans.

“I do think there is an issue if all schools are to become part of huge new chains, in which there is little accountability or parental involvement,” the MP said, the Observer reported today.

“If this move happens in the wrong way, there is a danger that instead of more freedom for schools we might see new and distant bureaucracies springing up.”

Mr Brady’s comments come after Conservative local councillors made their misgivings about the scheme public last month.

A Department for Education spokesperson said: “It is completely untrue to suggest there will be a shortfall of funding for our academisation plans. As set out in the Spending Review, and in last month’s Budget, we have enough funding 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.”