Councils will be given just 50 days to develop a plan to turn around schools where more than 70 per cent of teenagers fail to get five good GCSEs including English and maths.

There are 638 schools across the country and 82 in the Yorkshire region on the Government's hit list after failing to meet this target in last summer's exam results.

The Government wants all schools to get at least 30 per cent of its students reaching the benchmark by 2011.

Those who do not improve could be replaced by privately sponsored academies, trust schools or taken over by successful neighbouring schools.

Children's Secretary Ed Balls said that could mean grammar schools merging or forming partnerships with struggling schools in areas where selective education exists.

The Normanton MP announced yesterday that an extra £200m would be spent on top of the £200m pledged in the Budget to transform standards in struggling schools through the National Challenge Initiative.

Local education authorities will be given until the end of this term to show how they intend to improve failing school's results between now and 2011.

If improvements cannot be achieved the schools will be axed and replaced with academies, trusts or National Challenge trust schools, where they are taken over by nearby successful schools and form partnerships with universities or businesses.

Mr Balls said: "I think we've shown, in the case of the academies programme, that schools that have been stuck with low results for a long period of time, a change of governance, a new partner – a university or a business – often a change of head, a new injection of funds, can really change aspirations and get the school on a different track."

However, the list of schools which are not reaching the Government's benchmark includes 26 new academies – four of which are in Yorkshire.

The failing schools list also features 14 secondaries in Leeds, 10 in Bradford and Sheffield, eight in Barnsley and seven in Hull and Kirklees. Teaching unions urged Mr Balls not to name and shame schools in challenging situations.

Acting general secretary of the National Union of Teachers Christine Blower said: "If Ed Balls is to provide meaningful support to the 638 secondary schools he has identified he has to lift the threat of school closure for failing to meet arbitrary targets.

"No headteacher or teacher mindful of their career will join a National Challenge school if they think it will be closed and turned into an academy in the following year."

General secretary of the Association of Teachers and Lecturers (ATL) Mary Bousted said: "If the National Challenge does what it says on the tin – namely support these schools with increased resources, targeted assistance and, crucially, the brokering of local solutions between schools and local authorities – it has ATL's support.

"But if the National Challenge turns out to be more naming and shaming, a disgrace and failure of a policy, it will not improve school standards and the chances of the children in those schools."

Tory shadow children's secretary Michael Gove said: "Imposing yet more Government targets on struggling schools will do nothing to improve pupil achievement. They need to focus on discipline and behaviour and getting the basics right, particularly English, maths and the three sciences."