The spending watchdog says academies cost �27m on average

The report from the House of Commons Public Accounts Committee says there are signs that academies are beginning to raise standards.

But it says that academies are a "relatively costly means of tackling low attainment".

Academies are flagship schools intended to raise results in deprived areas.

The report from the committee examines the cost and benefits of the academy programme - launched by the government to create a new type of independent state school in areas with a record of educational failure.

Expensive?

It says that the average cost of building an academy is �27m compared to �20m to �22m for other secondary schools - and that 17 out of the first 26 had cost overruns of up to 10%.

Critics of academies have argued that any improvements in results at academies are a reflection of the scale of investment, rather than their autonomous status.

And the report says that the plan to open 200 academies in the next three years will have capital costs of around �5bn.

Our basis for judging academies is simple: do they improve results, and do they deliver for the most vulnerable kids? Michael Gove Shadow schools secretary

"Costs have not been kept under control, with 17 of the first 26 academy buildings each costing over �3m more than expected," said committee chairman, Edward Leigh.

"There is also no certainty about what it costs to run the new buildings in the longer term. This information is essential if funding and budgets are to be set at a realistic level.

"It is too early to give an overall verdict on the success of the academies programme. The picture so far is mixed."

At present, there are 83 academies, many of which are operating in the most disadvantaged areas and attempting to turn around a long legacy of underachievement.

'Worth the expense'

The government has always argued that the extra spending was a worthwhile investment, if it could achieve improvements in areas that had been the hardest to reach.

"Academy GCSE results are rising at a much faster rate than the national average," says a spokesperson for the Department for Children, Schools and Families.

"The National Audit Office report earlier this year was also positive, concluding that academies were on course to deliver good value for money."

But the ATL teachers' union said the report showed that academies were not good value for money - and the expansion plan should be halted.

"Academies are expensive, unproven, unaccountable and distort education provision," says the ATL's Martin Freedman.

But the Conservatives' shadow schools secretary, Michael Gove, said that academies were worth the expense - and more schools should be allowed similar independence.

"Our basis for judging academies is simple: do they improve results, and do they deliver for the most vulnerable kids?"

"This report acknowledges the unarguable fact that academies are a success in driving up results. The freedoms they have and the choice they bring helps those most in need," said Mr Gove.