Taxpayers will be asked to stump up another £10 million towards the cost of moving a major road to allow Birmingham Airport’s runway to be extended.

The long-awaited project can only go ahead once the A45 Coventry Road has been diverted at a cost of £32 million.

Regional transport body Centro’s chief executive, Geoff Inskip, told authority members that they would be asked to make a decision next month whether to contribute £10 million towards the scheme.

Birmingham City Council is already paying £15 million and the airport a further £7 million on top of the £65 million it will cost to extend the runway itself.

The seven West Midlands councils which make up Centro own 49 per cent of the airport’s shares.

Mr Inskip told a meeting of the Integrated Transport Authority that the runway would bring financial benefits for the whole region.

“There’s a funding gap of about £10 million,” he told members this week. “The Integrated Transport Authority will consider a report to fill that gap at its next meeting on December 13.

“The runway extension would provide a cross-conurbation benefit and that’s why Centro has been asked to donate.

“The business case is very good but it’s not in front of you right now.”

The runway extension will allow larger long-haul jets to lands pave the way for air links to India, China and America.

It could be operational by as soon as 2014.

A spokesman for Centro said that building a new road would allow the space for a proposed tram system serving the airport to be included.

“While the runway extension itself needs to be paid for by the airport the diversion of the A45 is part of the enabling works for the project,” said the spokesman.

“It also brings transport benefits in form of built-in road space for a future rapid transit system.

“Until the rapid transit system is in place this dedicated carriageway will be available for buses, helping to speed up journey times and reliability for passengers and improving people’s links to new job opportunities in the area.

“Adding this extra rapid transit pathway at a future date and after the road has been re-routed would cost considerably more so integrating it into the diversion scheme represents far better value for money.

“Because of the transport benefits of re-routing the A45 we will asking the Integrated Transport Authority on December 13 to approve a contribution from Centro towards the cost of the road’s diversion.”