In 2004 78% of 11-year-olds made the grade in English, 74% in maths

Education Secretary Ruth Kelly said those aged 11 to 14 would get "tailored tuition" in small catch-up classes.

The target group is the lower 50% of the 11-year-olds in England who do not reach the expected test level - about 57,000 in maths and 44,000 in English.

The Tories said Labour had promised to raise standards eight years ago.

Playing up

Ms Kelly said international comparisons indicated that England's 10-year-olds ranked third among developed countries in literacy.

"But I am not satisfied with that. Too many children arrive at secondary school below the expected standards in maths and English.

"That holds them back and can disrupt the education of other pupils when they play up in class," she said.

Labour said its plans would include more money so schools could pay for the extra staff they needed. Funding would be related to needs, to be used at head teachers' discretion.

A spokesman said the focus would be on schools which had a concentration of children who had difficulties.

There would also be tailored tuition for seven-year-olds who struggled to keep up and for "gifted and talented" primary school children.

Resourcing

Heads have been sceptical about Labour's recent pledges of more personalised tuition, arguing that the necessary resources are not there.

Schools must be allowed to judge how they will meet the special needs of pupils of a wide range of ability David Hart National Association of Head Teachers

The leader of the National Association of Head Teachers, David Hart, said the money must be new and be provided on a long-term basis - and go straight to schools.

"I do not want to see this cash spent on yet more local authority advisers. Schools must be allowed to judge how they will meet the special needs of pupils of a wide range of ability," he said.

On Monday the director general of the Confederation of British Industry, Sir Digby Jones, advocated repeated testing of 11-year-olds until they had mastered the basics - which he said were fundamental to improving the nation's skills.

New strategy

Shadow education secretary Tim Collins said: "Eight years ago, Mr Blair promised to raise standards. All talk.

"Today one in three 11-year-olds leaves primary school unable to write properly and one in four can't add up properly."

A Conservative government would replace the national literacy strategy with new guidance based exclusively on synthetic phonics, where children are taught letter sounds and how they blend into words.

"This approach has been shown to improve pupils' reading scores dramatically in Scotland - we are confident this will be repeated south of the border," he said.

Liberal Democrat spokesman Phil Willis said it had taken years of campaigning by his party for Labour finally to realise that small classes made "a huge difference".

"It's not targets, testing and league tables that improve a child's education, it's smaller class sizes and high quality teaching."