The Treasury is poised to axe Crossrail, the scheme to improve public transport links in London, because private investors are refusing to get involved.

"Crossrail will not go ahead unless the private sector comes up with most of the investment and there is no sign of that happening," a Treasury official told the Guardian.

A spokesman for the DfT told ePolitix.com: "Nothing has changed. We are still committed to the Crossrail scheme.

"We have asked Crossrail to start consultations - and that is what they are doing."

Simon Hughes, Liberal Democrat mayoral candidate, said: "Crossrail is vital to the future vitality of London and must be completed as soon as is practical.

"London is one of the few cities in Europe without a coherent transport system that gets passengers from east to west or north to south leaving many people stranded in the capital.

"With congestion increasing on London's underinvested and overstrained train and tube lines, it is critical that the new Crossrail project is completed with a real understanding of London and Londoners needs.

"I expect the project to be funded mainly out of the private sector. However, the more positive the government can be about innovative ways of raising money, such as collecting money from windfall profits on commercial properties on the route, the more confidence investors will have that Crossrail can become a reality."

Forum Response: Crossrail

Norman Haste, chief executive, said: "This is a unique chance to make a significant difference to public transport and life in London and in the country.

"Cross London Rail Links Ltd is the company the government set up to deliver the Crossrail railway network to the capital - and that is what we are determined to do.

Sir Christopher Benson, chairman, said: "Crossrail is the great opportunity to enhance the lives of Londoners and visitors. It willcontribute hugely to London's pre-eminence as the capital of European finance and business."

Forum Response: British Retail Consortium

David Southwell, spokesman for the BRC, told ePolitix.com: "There is no magic bullet that can solve London's transport problems.

"However, Crossrail stood to make a useful contribution to reducing the pressure on a chronically under-invested transport infrastructure which is rapidly losing the confidence of both the business community and its millions of users.

"More needs to be done to ensure that London's transport system lives up to the requirements of a global retail capital in the 21st century."

Forum Response: Construction Products Association

Chris Bennett, external affairs executive at the CPA, told ePolitix.com:"In 2000, the government used the ten year transport plan to set out its strategy to bring the UK's transport infrastructure back from the brink.

"The need for investment is nowhere more evident than in London, where there was already serious overcrowding, with over three million journeys a day on the London Underground -more than the entire rail network in the UK.

"The plan crucially identifies a 'new east -west rail link, such as Crossrail' across London as a vital component to sustain London's economic growth and take pressure off the existing underground system.

"Following the serious problems which have affected the Central and Northern lines over the last twelve months, any decision to cut the Crossrail scheme from the plan would seem to fly in the face of reason.

"As recommended in its recent report, 'Achievable targets? Is government delivering?', the association believes that the government must now set targets for the implementation of Crossrail in the period up to 2015 and provide the necessary funding and leadership to ensure that the project is delivered."

Forum Response: Institute of Directors

A spokesman for the IoD told ePolitix.com: "The private sector certainly has a role to play on the finance side of Crossrail.

"But the most important requirement is a sense of urgency for this vital project.

"This is where politicians must start to give a stronger lead. London's transport infrastructure has to be improved, and ultimately it is the government's responsibility."