A new Government Regional Growth Fund for economic development could contribute £15 million to kick-start Birmingham Airport’s runway extension.

Councils and business leaders in charge of the Birmingham-Solihull Local Enterprise Partnership want the RGF to meet almost half the £32 million cost of diverting the A45 Coventry Road to enable the 350-metre runway extension to be built.

Uncertainty about how the road diversion will be paid for is continuing to hold back the runway project, which is seen as a vital trigger for economic growth.

Centro, the passenger transport authority, will give £10 million toward the A45 cost, with the airport contributing £7 million. Birmingham City Council has promised to find £15 million, but public spending cuts faced by local government could put the pledge in doubt.

The proposal to include the A45 scheme in one of eight priority bids for the first round of LEP funding was criticised by West Midlands Friends of the Earth.

Spokesman Chris Crean said: “If the airport wants to extend its runway then it should pay the full cost itself, including moving the A45. We do not believe there is any justification for a commercial project like this being funded by the public purse.”

Mr Crean hit out at the allocation process for RGF bids, overseen by an interim assessment panel set up by the shadow LEP board.

He said: “Who are these people deciding which projects to bid for?

“There is no public scrutiny, no transparency and no democratic input into this.”

With the longer runway in place, Birmingham Airport will be able to compete with Heathrow, Gatwick and Manchester by offering non-stop flights to cities in China and India and to the west coast of America for the first time.

An application for financial assistance is one of eight bids from the partnership for RGF funding totalling £54 million.

A separate bid for financial assistance is expected to be submitted by Jaguar Land Rover.

The RGF will operate across England from 2011 to 2014 and replaces a cash fund previously administered by the regional development agencies.