A new high-speed rail line linking Birmingham, London and Manchester "could be the answer" to getting Britain's rail system moving, Transport Secretary Alistair Darling said yesterday.

The track, with trains running up to 225 mph, would boost the economy and help the environment by getting travellers out of their cars, he said.

Mr Darling's comments, in a speech to rail industry managers, suggested he was prepared to back the £30 billion scheme, but he insisted no final decision had been made.

Former British Airways chief executive Rod Eddington is considering the proposal, as part of a wide-ranging review of Britain's transport system.

Mr Darling also stressed the need to improve transport infrastructure in regions such as the West Midlands, rather than concentrating funding in London and the South-east.

The proposed high speed rail line line would run from London to Scotland, stopping at Birmingham and Manchester.

It would be faster than the upgraded West Coast Main Line, which recently began a 125mph service between London Euston and Glasgow.

Speaking at the National Rail Conference in London, Mr Darling said: "We need to rigorously examine the merits of high speed lines in this country.

"A high speed line could improve journey times and bring potential economic benefits."

It could have a similar effect to the Channel Tunnel Railink, which had bought billions of pounds worth of regeneration to parts of London, he said.

"It could, provided we get it right, bring environmental benefits by getting more people out of their cars and off aeroplanes."

Mr Darling added: "A High Speed Line could be the answer, but we understand the complexities of the problem."

Mr Darling also stressed the importance of improving transport links in cities such as Birmingham.

"Britain's towns and cities will drive our economic success in the future.

"Birmingham, Leeds, Manchester - and they will all face growing pressures. That is why we need to act now, both on road and rail.

"The capacity problems they face are different to London, because people's travel patterns are different.

"The peaks are much shorter and more pronounced. But if we want our towns and cities to grow we need to support them - and so these problems need to be addressed."

Coun Gary Clarke, chairman of the West Midlands Passenger Transport Authority, welcomed the comments.

But he added: "We must now ensure we get our fair slice of the cake.

"Network capacity really is critical in the West Midlands which lies at the hub of the national network.

"We have inter-city, cross-country, suburban off-peak and essential commuter services all competing for the same track.

"And when we get rail grid-lock in the West Midlands there is very quickly a knock-on effect for the wider network."

Local councils in the West Midlands are seeking Government funding for the rebuild of New Street Station.

But it will cost £500 million just to give the station sufficient passenger capacity. Improvements to rail track are also needed, to deal with a bottleneck at the station.