Birmingham will hold a referendum on creating a directly-elected mayor if the Conservatives win the next election, David Cameron will announce today.

The Conservative leader will publish detailed plans for dramatic changes to local government, which also include the abolition of regional development agencies, the Government quangos responsible for helping local businesses. Their powers and funding will go to local councils instead.

Residents in England’s 12 largest cities, including Birmingham and Coventry, will vote on whether they want their own version of London mayor Boris Johnson, under the Tory plans.

Lord Heseltine, the former Deputy Prime Minister, will oversee the referenda, and decide the exact wording of the question to be put to voters.

Mr Cameron supports a directly-elected mayor for Britain’s major cities, including Birmingham, and that local people should have the final say on how they are governed. But he will go further with a promise that a Conservative government will hold a ballot whether local councils want them or not, as he launches the policy with Meriden MP Caroline Spelman, Shadow Secretary for Local Government, on a visit to Coventry.

The announcement is unlikely to be welcomed by Mike Whitby, the Conservative leader of Birmingham City Council, who has opposed calls for a referendum on whether to introduce a mayor. Councillor Whitby was unavailable for comment.

Under current legislation, introduced by Labour, a vote takes place if at least five per cent of voters sign a petition asking for one within a year. But attempts to force a referendum in Birmingham ended in defeat last year, after campaigners were unable to collect the 36,000 signatures needed.

Speaking to the Birmingham Post, Mrs Spelman said: “Boris Johnson has set a very good example as mayor of London.

“Why shouldn’t Britain’s 12 largest cities have the same opportunity that London has enjoyed? And they are free to decide whether they want it or not.

“Our proposal would be to do this very simply in all 12 cities on one day, as part of a national campaign.”

Britain’s big cities were not as wealthy or successful as similar cities on the Continent, she said. “A strong character with skill and vision can really make a difference to a large city. If you look at cities like Liverpool and Manchester and Birmingham, we want them to match the economic success of their counterparts in Europe.”

She stressed that Birmingham’s residents would have the final say on whether to introduce a mayor.

But critics of the policy are likely to argue that mayors concentrate too much power in the hands of one person, and actually reduce local democracy by giving councillors far less power to hold the city’s leadership to account.

The other major change being announced today is the abolition of Advantage West Midlands, the regional development agency created by Labour, which spends about £300 million a year. Under a Conservative government, councils will receive the money to spend on helping local economies as they see fit.

They will be encouraged to work with neighbouring authorities and create “local enterprise partnerships”, Mrs Spelman said. This would probably mean Birmingham, Solihull, Wolverhampton, Dudley, Walsall, Sandwell and Coventry creating their own development agency, possibly including Telford as well.

Other councils such as Worcestershire and Herefordshire would be free to form their own development body, perhaps joining forces with Gloucestershire to create a “three counties” agency. Boundaries would be decided by councils and not by Whitehall, Mrs Spelman said.