BBC Education Correspondent Mike Baker follows Mr Blair's mouse clicks

Tony Blair said it would be like having "the best library in the world in our classrooms."

He was at Trimdon Village Primary School in his constituency of Sedgefield, County Durham, being helped in his Web access by 10-year-old Nikita Fellows.

Tony Blair: "Learning revolution"

He visited a new national archives site from the Public Records Office - tailored for schools - and was able to read about Trimdon as far back as 1882, seeing pictures of the Trimdon Grange mining disaster.

Mr Blair said: "The investment announced today will prevent a generation of children emerging who don't have these skills - the information poor.

"This national archives site from the Public Records Office shows how content providers can develop good learning resources for the grid, which will stimulate children's interest.

"Before this development, unique and important documents could be read only by visiting the Public Records Office in person, but now they can be delivered directly to classrooms, homes and libraries throughout the UK via the internet.

"That is the kind of learning revolution that will now become possible for every child in every school in the country."

Thanks to help from computer companies trained staff are on hand at this Berkshire school

The idea is that the grid will allow pupils access to remote libraries and museums, enable teachers to share ideas and parents to help children with their homework - all over the Internet.

The four-year target is to connect every school to the Internet and train all teachers how to use it.

Tony Blair announced new funding of £450m for the years 2000-2002, on top of the £102m available this year and £105m for next year already announced.

Mr Blair also challenged businesses to play their part in developing educational hardware and software for schools.

Patchy

The task of getting schools online remains huge, however. Only one in five teachers has been trained to use computers and inspectors' reports suggest that many schools are struggling to meet the demands of information technology.

Sceptics: "Bill Gates does not do my homework"

Some schools have well-motivated information technology teachers and have invested heavily in computers that are well used.

In others - primary schools especially - there are teachers who are nominally in charge of information technology but who have never even used the Internet themselves.

David Blunkett: "As my son would say, 'Get real' "

Some teachers - while welcoming the investment - wonder if the money would not have been better spent overcoming the shortages of teachers skilled in maths and science and - ironically - information technology.

There is also concern in some quarters that the emphasis on educational use of computers and the Internet will disadvantage children whose families cannot afford to match their schools' facilities at home.

But the Education Secretary, David Blunkett, says the country cannot avoid the inevitable progression of technology - and that all youngsters will be disadvantaged if this investment is not made.

Better that the children have access at school, at least, than not at all, he argues.

He is also establishing after-school homework clubs in one in four primary schools, and he wants to see the manufacturers of computer games machines broaden their use for educational purposes.

Speaking on the Today programme on BBC Radio 4, Mr Blunkett stressed that the £230m the government is spending on training teachers to use the new technologies is in addition to the money announced by the prime minister for hardware and Net access.

Unions welcome the funding but wonder if it is enough. The Secondary Heads' Association says research has indicated that the amount spent on training should at least equal the money spent on equipment if systems were to be successful.