There is “no point” creating a mayor whose powers are limited to just one local authority area when key public services cover larger regions, a major study has concluded.

Mayors should represent an area’s “economic footprint”, said a high-powered inquiry led by Warwick University.

Researchers interviewed 42 mayors, staff and senior council figures in the UK, Canada, Australia, New Zealand and the US too ask what role elected mayors can play in providing strategic leadership to cities.

The findings were published in a report by the Warwick Commission, chaired by Professor Wyn Grant, of Warwick University’s Department of Politics and International Studies. Other commissioners included senior figures from business and politics, such as KPMG director John Atkinson, Lib Dem peer Lord Shipley, the former Leader of Newcastle City Council, and Alexandra Jones Chief Executive of think tank the Centre for Cities.

The report warned that it was still unclear what powers a mayor will have - and this may “undermine the possibilities of some cities voting for a mayor” when referendums are held in cities including Birmingham and Coventry on May 3 to ask voters whether they want to switch to a mayoral system.

It added: “A further difficulty is the political and geographical boundary of any mayor, for while most are designated as local authority mayors there are good reasons to suggest that a political mandate needs to coincide with a viable economic footprint.

“In other words, there is no point in electing a mayor whose remit does not cover the necessarily boundary-spanning regions that could foster economic growth – the so-called Metro-Mayor.”

They highlight an example in Australia where it was only the election of a mayor whose authority crossed local authority boundaries that allowed improvements to be made to transport services.

“The utility of this is perhaps best seen in Aucklan where Len Brown was elected as Mayor of the ‘Supercity’, an administrative region that replaced the previous eight directly elected local mayors with a single city region.

“This has allowed the Mayor to unlock the administrative blocks that have bedevilled the city’s transport infrastructure for years.”

Mayors are also likely to face obstacles because of austerity measures which will limit their ability to make changes which involve spending money, the Commissioners warned.