The fate of hundreds of “failing” schools in the first year of a Conservative government could depend on how long a political party has controlled their local council.

Michael Gove, shadow schools secretary, this week announced plans to intervene immediately in many of the 638 schools where less than 30 per cent of pupils achieve five GCSEs including maths and English at A*-C grade. These schools would be taken out of local authority control in the first year of a Tory government, he said, and turned into semi-independent academies.

But he said a critical factor in deciding which secondaries would be taken over would be the political make-up of their local authority.

“Crucially, if the school has been run by the same local authority, with the same party in control for the previous 10 years, then why should the local authority be allowed to continue failing our children?,” Mr Gove said in a speech to the Centre Forum think-tank.

Labour-controlled Manchester, Sunderland and Knowsley, on Merseyside, were cited as examples.

The Government has given schools that are missing the benchmark until 2011 to improve or face takeover by an interim executive board or a successful neighbour, replacement with an academy, or closure. The Tories would increase the stakes by making the opening of new academies the only option, and intervening as soon as the party came to power. However, one organisation that Mr Gove cited as a potential sponsor told The TES it doubted whether there would be the capacity for so many takeovers.

There are caveats that would prevent all 638 schools from being targeted immediately, but Mr Gove confirmed he would expect hundreds of takeovers within a year.

Asked about a TES analysis showing that two-fifths of the schools had above-average contextual value added (CVA) scores, he said this would mean they were not “top of the queue” for intervention.

Schools showing signs of real improvement may also be given a stay of execution under the Tory plans.

But Mr Gove warned: “It is not good enough to say you are doing well on the CVA score when two-thirds of children are not getting five good passes. The onus has to be on the people running these schools to show why they shouldn’t be shifted into new management.”

Jim Knight, schools minister, said: “Michael Gove should explain why there are more under-performing schools in Tory-run Kent than any other local authority.”

Kent operates selection, and most schools not meeting the benchmark are secondary moderns. Mr Gove’s plans are for comprehensives.

Comment, page 27.