The West Midlands bid to win £2 billion for public transport improvements by piloting a controversial road pricing scheme has been rejected by Ministers.

The Government has ordered the region to rethink its plan, saying the proposed timetable for introducing road charges is unacceptable.

Transport Minister Stephen Ladyman said there were serious doubts about the West Midlands plan and indicated it was unlikely the region would receive all the money it had asked for, even if the bid was successful.

But Dr Ladyman insisted a national road pricing scheme was likely to go ahead and warned that there simply was not enough room to build new roads. Instead, car use would need to be managed with congestion charges to lower demand, he said.

The Minister was speaking to The Birmingham Post after seven authorities including Birmingham, Coventry and the Black Country councils, submitted plans for a road pricing scheme in the West Midlands.

The Growth or Gridlock study commissioned by the councils and published last month suggested a range of options including charging motorists up to £5 a day.

In return, it called for the Government to provide £2 billion for public transport improvements, and predicted another £2 billion could be raised from the charges themselves.

Greater Manchester authorities have also drawn rival proposals for piloting road pricing, in the hope of receiving the funding themselves.

The Government hopes to use a regional scheme to test out methods of charging motorists ready for a national launch in 2015.

But Dr Ladyman pointed out that the West Midland councils had proposed starting their local scheme in 2014 - leaving no time to test it thoroughly.

He said: "We have to come up with a coherent and logical way of testing road pricing, taking us to a national scheme.

"The West Midlands would be looking for a £2 billion boost in transport investment and they would introduce a scheme that would lead to road pricing [in the West Midlands] in 2014. But we are interested in going into a national road pricing scheme around 2015. So 2014 doesn't give us a lot of time.

"We have gone back to the West Midlands to ask if 2014 is as quickly as it can be done, because clearly it is going to have an impact on whether to go ahead with the West Midlands scheme or not."

He also cast doubt on the region's hopes for massive Government investment in public transport.

"They have suggested a £2 billion package. Well, a £2 billion package wouldn't leave a huge amount of money for other schemes."

A spokesman for the seven West Midlands authorities said: "We understand the Government is keen to push the congestion timetable along. The West Midlands shares this serious commitment to tackling congestion and that's why we have been the first region to kick off this vital public debate.

"What is clear is that doing nothing is not an option."