Transport chiefs in the West Midlands need to come up with a “Plan B” as they press ahead with a scheme to expand the Midland Metro, according to campaigners.

The call from Kevin Chapman, chairman of the West Midlands Campaign for Better Transport, comes as West Midlands transport authority Centro faces a £253 million gap in funding for the expansion plans.

The expansion would see the current 23-stop line between Birmingham Snow Hill and Wolverhampton St George’s extended further into Birmingham city centre and out from Wednesbury to the Merry Hill shopping centre at Brierley Hill.

There are also plans for a £30m extension in Wolverhampton city centre linking St George’s with the city’s bus and rail station.

A second phase would link the five Ws – Wolverhampton, Wednesfield, Willenhall, Walsall and Wednesbury as well as links to Birmingham International Airport and park and ride car parks in Quinton and Great Barr.

So far the only private investors are the Merry Hill centre’s owners Westfield, who have pledged £36m, and developer Ballymore which is building a flyover bridge in Birmingham City Centre.

Mr Chapman added that Centro should come up with a contingency plan in case the hopes to expand the service fail.

He said: “Centro really needs to come up with a workable Plan B, which could mean guided bus routes and extensions of rail services.

“I can certainly sympathise with businesses who do not want to be taxed to pay for it but the advantages of fewer cars on the roads mean they will be able to get their goods out sooner.”

Last month the Express & Star exclusively revealed that homes close to the proposed new Metro line could be more expensive, because a £2,500 levy may be added to their selling prices.

Companies across the region may also be expected to fund the scheme year through their business rates. The plans, revealed in a report by transport body Centro, are part of ambitious proposals to raise £210m to extend the tram system through the Black Country.

The value of new homes could rise if they are built close to new stops, therefore it is suggested developers would have to pay more to build close to lines.

It would leave a shortfall of just over £40m, 10 per cent of what transport bosses originally expected the Government to provide for extensions.