Both Labour and the Conservatives have put promises to devolve power to regions such as the West Midlands at the heart of their election campaigns.

Labour leader Ed Miliband even compared the level of autonomy that would be available to the extensive powers devolved to Scotland.

And George Osborne, the Conservative Chancellor, confirmed during a campaigning visit to Dudley that the region could be next in line for a major devolution package similar to the one already granted to Manchester.

Labour will give combined authorities, which involve neighbouring councils working together, control over bus and local rail services.

Councils would be allowed to dictate where buses should run and how often, with bus companies continuing to provide the service.

They would also control job programmes designed to get unemployed people into work and make decisions about training schemes in the region, to ensure young people were taught the skills employers needed, as well as having more control over where new houses were built.

A total of £30 billion currently spent by central government would be transferred to local councils.

Mr Miliband said: “Labour will create regional powerhouses in every corner of the country.

“It will bring devolved powers in England closer to those enjoyed by Scotland and Wales.”

But Labour’s Shadow Local Government Secretary, Hilary Benn, stressed power would only be devolved to combined authorities.

While a number of regions have already created such authorities, Birmingham and the Black Country councils are still working on setting one up.

Mr Benn said: “Councils and the communities they represent want to have more say over their future... in return, councils will have to come together to collaborate.”

Conservatives also back plans to devolve power to local councils – and George Osborne, the Conservative Chancellor, has already signed a deal with Greater Manchester councils giving them £1 billion worth of powers over transport, housing, planning and policing.

But speaking to the Birmingham Post, he confirmed Birmingham and the Black Country could be next.

He said: “I think it’s perfectly possible to have a really big act of devolution here in the West Midlands.

“You’ve got authorities that are ready to work together and a real appetite to make sure we have local people in control of things like the transport and the skills budget.

“And I think Birmingham and the Black Country is really the next big place in our country where we can trust local people to make decisions.

“This is part of the Conservative plan about re-balancing our economy, making sure we don’t place all our bets, like the last Labour government did, on the city of London.”

The battle for power

Our interactive poll-of-polls draws on every opinion poll published by each of the main polling companies over the last 100 days: