An independent think-tank has called for metro mayors to be introduced in city-regions across England.

The Cities manifesto from the Centre for Cities calls for elected mayors in Greater Manchester, Birmingham and Leeds.

As the general election campaign got under way, the group set out its policy challenge to the political parties.

The mayors would be accountable to the whole region – and would not be subordinate to the local authorities.

Once the system is in place, the manifesto calls for the system to be rolled out to other city-regions throughout the country.

The Government should also relax regulations about where developments could be built, according to the report.

The think-tank has called on whoever forms the next government to scrap the national target of 60% of new dwellings being built on brownfield land.

It also calls for councils to keep some of the money raised from land auctions to help boast the local economy.

The report was welcomed by the South East Diamonds for Investment and Growth (SEDfIG) group.

SEDfIG chairman and leader of Basingstoke and Deane BC, Cllr Andrew Finney, said: ‘It is absolutely essential for any future government to ensure that these areas are given the right freedoms and incentives to flourish and help drive the recovery of the UK economy.

‘Major investment in local and sub-regional transport capacity is needed immediately to relieve congestion, particularly on strategic corridors, such as Oxford-Milton Keynes-Cambridge and in the Thames Valley.

‘We would welcome financial incentives for growth, such as control over business