Shadow education secretary Michael Gove said the Tories would make support for the most disadvantaged children a priority if they win power.

Gove said that up to 640 of the worst secondary schools in England would be removed from council control and be turned into city academies, charitable trusts or parent co-operatives.

"We will help new schools set up in areas where local authorities have let parents down," Gove told the Telegraph.

"But, in areas where the same party has been in power for too long, and where standards remain poor, we will have the most failing schools transferred to academy sponsors and others who have a proven record of improving education for the poorest. We will bring forward legislation to do so in the first Queen's speech."

Under the Tory strategy, city academies and other groups could take over local authority schools. They would receive funding directly from central government, but would be free - as academies are - to raise their own additional funds.

They would be required to spend at least the same amount on each pupil as councils do. The schools would then operate independently.

Gove said: "The areas of greatest failure can be clearly identified. There are more than 630 schools across England which can't even generate five decent GCSE passes for a third of their students.

"The government has defined these as the schools where special attention needs to be focused. They are right. It's appalling that you can educate children for 11 years, with the state devoting more than £5,000 every year to every child, and then have schools where more than two thirds of children cannot secure a basic portfolio of qualifications.

"While ministers tell us, like the board of Northern Rock, that their figures can be trusted and their phenomenal achievements are soundly based, the external audits tell a very different story. When we judge our performance against the reality of what other nations are achieving we're falling behind."