Railtrack has revealed plans for a major expansion of the rail network as part of a �52bn spending programme.

However, the company has so far only committed itself to spending �3bn.

It says it cannot afford everything and wants the industry to decide which projects are the most urgent.

It plans to modernise the West Coast main line to Scotland, improve Thameslink and extend Sunderland's Metro.

It also recommends upgrading the East Coast main lines, Great Western, London to Stansted and the North Trans Pennine lines.

The 12-year spending plan, designed to cope with growing passenger numbers and the continuing decline of the network, is mostly only a wish list.

Chief executive Gerald Corbett said: "The �52bn is the total menu to choose from and it includes maintenance and renewal."

He said the group's immediate focus would be its plans for the next five years.

Steve Marshall, Railtrack's finance director, said he did not expect the final investment to reach �52bn.

He said: "You do not go into a restaurant and order the whole menu, you make choices.

The Paddington rail disaster last year sparked calls for drastic action from Railtrack to improve the network.

Campaigners demanded more money be ploughed back into the rail infrastructure after it emerged that Railtrack was making more than �1m a day, with pre-tax profits of �428m last year.

Jonathan Bray, spokesman for pressure group Transport 2000, said: "Railtrack have got a lot to prove. People will be on their guard until we start to see them deliver on their promises."

But he added that �40bn was getting close to the amount of investment needed to bring Britain's rail network into line with its continental peers.

Who will pay?

The annual Railtrack Network Management Statement, which contains the spending plans, comes as three separate industry reviews consider who will pay for the upgrades.

The Office of the Rail Regulator is assessing how much it will allow Railtrack to charge train operating companies to use its track.

A 10-year plan for public transport is being considered by the government.

And the Shadow Strategic Rail Authority is negotiating which companies will run the next set of rail franchises.

Last year Railtrack put its 12-year spending plans at �27bn.

Analysts predict that this year's budget will see an increased amount set to be channelled into network improvements.

George Muir, director general of the Association of Train Operating Companies, said: "The system is already busier than ever in history, and it is encouraging to see train operators' ambitious plans emerging to provide additional capacity to meet demand and to provide a better service to people."

He said the improvements identified by Railtrack were "by no means all commercially fundable" and urged the government to make a contribution.

He said: "Passenger train companies have consistently contributed �200m a year to the Treasury's coffers.

"We would like to see that sum, and more, ploughed back into investment in the industry to the benefit of new and existing passengers."