Mounting frustration at the failure to secure Government funding for the Midland Metro tram extension through Birmingham city centre could result in the business sector withdrawing its backing for the £180 million plan.

Business leaders doubt whether cash for the scheme, and for a second metro extension in the Black Country, will ever be forthcoming and are discussing whether the region ought to be lobbying for more buses instead of trams.

Birmingham Chamber of Commerce and Industry chief executive Jerry Blackett admitted yesterday that the business community was split over whether it was worth continuing to campaign for the new metro routes.

Mr Blackett, who chairs the influential West Midlands Business Transport Group, said: "I don't think we have finished the discussion properly in the region as to whether we are really committed fully. We have got to have a debate about the level of unity for the metro."

While he personally remained in favour of a "fully integrated" tram network if it could be shown to be value for money, he doubted whether the Government would be prepared to approve the £320 million requested for the two extensions so soon after agreeing this month to pay £400 million to redevelop New Street Station.

Mr Blackett added: "We have put together a well argued transport strategy for the West Midlands but we still haven't answered the big question of where we are going to get the money from. We are nowhere near getting the money and we can't see it coming soon. Although it is not sexy, if you improve bus services you could move a lot of people around and tackle congestion."

His comments came after it emerged that passenger transport authority Centro and Birmingham City Council are considering pressing ahead with the Snow Hill to New Street section of the metro extension irrespective of whether Government funding for the entire project is approved.

Publicly, Centro and the council are committed to delivering the scheme in its entirety, from Snow Hill to Five Ways via New Street and Broad Street. But The Birmingham Post understands work is under way to examine how the Snow Hill to New Street section might be delivered by 2013 - the target date for completion of work on New Street Station.

The cost of such a scheme is believed to be between £50 million and £70 million and the work could be partly funded through Section 106 planning gain payments from city centre regeneration projects.

The idea has the backing of council leader Mike Whitby, who recently called a high-level meeting to discuss how the proposal might be progressed as quickly as possible. He is also keen eventually to push the metro eastwards, from New Street to Birmingham International Airport and the NEC.

Mr Blackett said: "The strategic thinking is if we have this bit of line we can get the metro visible on the streets of Birmingham and the public can appreciate what you get if you have a modern light rail system. It is a pragmatic approach."

He said his fear was that Government "cynicism" about trams would leave Birmingham with only the Snow Hill to New Street section running and no chance of completing the rest of the route.

Councillor Len Clark (Con Quinton), Birmingham's lead representative on the West Midlands Passenger Transport Authority, said: "The notion that we want to get the metro to New Street in time for the opening of the new station is credible. But we do not want to jeopardise the full programme."

A Centro spokesman said: "We are continuing to press for funding for the city centre extension in its entirety."

A Government decision about the two metro extensions may be made by the end of the year.

But Ministers have indicated approval is likely only if West Midlands councils submit proposals for road pricing and congestion charging schemes.

The planned metro route through Birmingham city centre is: Snow Hill, Bull Street, Corporation Street, Stephenson Place, Pinfold Street, Victoria Square, Paradise Circus, Broad Street, Five Ways.