The project, expected to go to ministers for approval next week, will make it easier for teachers to purchase computers by giving them a subsidy of at least pound;200.

Teachers will be encouraged to buy laptops, which are more expensive than standard desktop models. The cheapest laptops cost about pound;1,000, while desktop machines retail at pound;700 or less.

Nigel Paine, chief executive of the Technology Colleges Trust, said it was reasonable to expect teachers to pay between 25 and 50 per cent of the computer’s cost.

Research has found that laptops greatly benefit teachers. Of the 9,000 who were given one in the Government’s “Multimedia Portables for Teachers” project last year, 80 per cent said the laptop saved them time and 92 per cent felt it made them more efficient.

However, a range of both desktop and laptop models will be offered in the scheme by government-approved companies.

The Department for Education and Employment recognises that training is vital if teachers are to make the best possible use of the equipment.

Subsidies will be linked to the National Lottery-funded training programme.

This helps teachers use information and communications technology effectively in the classroom. The aim is for staff to work through distance-learning training materials on their own computers.

Officials are keen to ensure the national scheme does not cut across plans being developed by some training consortia offering to give teachers discounted computers.

The Government is thought to be willing to put in more money and this will be necessary if it is to reach a quarter of England’s teachers - about 100,000 staff. Assuming a subsidy of pound;500, the pound;20 million would help only one teacher in 10. There was speculation earlier this year that every teacher would be given a free computer, but the cost would have been about pound;400 million.

Mike Smith, professional officer for the National Association of Advisers for Computers in Education, welcomed the scheme. “All the evidence shows that personal ownership of a computer is a critical factor in teachers becoming better users of ICT in the classroom,” he said.

A similar scheme in Scotland is about to be announced. In March the Prime Minister, promised that all 40,000 Scottish teachers would get a personal computer by 2003. However, a source said the scheme is likely to operate a first-come, first-served basis.

That may help the Government escape claims that Scottish teachers are being favoured over their English colleagues. Scotland led the way by giving teachers access to cheaper computers in 1995.

Other countries have taken action to offer their teachers computers as part of an overall drive to promote the use of technology in schools.

Sweden plans to give 60,000 teachers - 40 per cent of the total - a multimedia computer in a pound;110 million, three-year programme, while the Australian state of Victoria is offering its 36,000 teachers a laptop for about pound;180 with payments spread over three years.