Faltering plans to extend the Midland Metro received a major boost today after an influential MPs' report demanded Government support for light rail schemes.

The Transport Select Committee report said light rail projects were not "crackpot" and should not be "written off as too expensive".

Last night transport bosses in the Midlands called for the Department for Transport to clear up the "uncertainty" surrounding the planned extensions to the Midland Metro.

The report, published today, said "the Government no longer wholeheartedly supported trams" and called for Whitehall to improve the planning and approval process for light rail schemes.

The MPs inquiry found that tram schemes in the UK can take up to 15 years to deliver compared to four or five years elsewhere in Europe.

West Midlands Passenger Transport Authority chairman Coun Gary Clarke said the report was full of "common sense".

"If the Government takes these findings on board we can clear up some of the uncertainty.

"It could even lead to Britain adopting some of the cheaper and faster construction methods used on mainland Europe." Midland Metro Line One - from Birmingham Snow Hill to Wolverhampton - was first conceived in 1986 but opened in 1999.

Crucial extensions through central Birmingham and the Black Country are still waiting to progress and significant doubt hangs over a proposed wider network, with three further lines through the region planned.

The committee, chaired by Gwyneth Dunwoody MP, found optimism for light rail schemes no longer existed and was concerned that funding for schemes in Manchester, Leeds and Hampshire had been withdrawn by the DfT, which "appears to have developed a preference for bus over rail-based schemes".

Mrs Dunwoody said: "Trams aren't a magic answer, but they certainly aren't anywhere near as crackpot as some people would have us believe."

She added: "Tram schemes cannot simply be written off as too expensive. The problems come because the Government takes a long time to make decisions, the private sector is supposed to bear the risks, then everyone seems surprised that those risks now have a price attached."

Line One is now the most reliable public transport in the region and more rush-hour trams have recently been added to cope with growing demand.

However, the National Express Group, which runs the scheme, bore £11 million losses between 2000 and 2003.

Rob Donald, director general of Midland Metro promoter Centro, said: "We need a DfT framework that considers the options, gives value for money and leads to a good deal for passengers - but then allows us to build tram lines cheaper and quicker.

"This inquiry has highlighted some very important truths that must be aired if we are to deliver an integrated transport system with the same speed and efficiency of other European countries."

The report said the DfT "failed to give a strategic lead in the development of light rail" and refused to trust local authorities' estimates of their own requirements.

Last night, a spokesman for the DfT said some light rail schemes do have a future. But he said they need to be put forward "as part of a coherent transport policy, integrated with buses" and represent "value for money".