National politicians who have made their names at Westminster could become the mayors of Britain’s great cities, David Cameron has predicted.

The Prime Minister said the creation of powerful city mayors would “renew” British politics.
He was speaking in Downing Street, at a reception to back the Government’s campaign to promote city mayors in the run-up to a referendum on May 3 which will decide whether Birmingham transforms the way it is governed.
He said: “I think a new generation of mayors in our cities will fundamentally enrich our politics as a whole.
“I look across the world and I see great politicians who run cities who then go on into national politics, and indeed you see national politicians go into city politics.
“I think that would enrich our political culture right here in the United Kingdom.”
In Birmingham, city MP Liam Byrne (Lab Hodge Hill), currently Labour’s shadow work and pensions secretary, is a national figure who is keen to stand as city mayor.
As well as his role in the Shadow Cabinet, he was appointed by Labour leader Ed Miliband to head the party’s policy review, following its 2010 General Election defeat.

Labour already has three potential candidates for mayor of Birmingham, with Edgbaston MP Gisela Stuart, former city MP Sion Simon and former council leader Sir Albert Bore all hoping to be selected.
Liberal Democrat MP John Hemming (Birmingham Yardley) has said he might stand for his party.
Birmingham City Council Leader Mike Whitby is in prime position to become the Conservative candidate. It remains to be seen whether any other Tories will come forward.
A major new collection of essays by leading think tank the Institute for Government has also highlighted the potential for politicians to cross over from national politics to running major cities.
The Institute, which has links to former Labour Minister Lord Adonis and senior Conservative Michael Heseltine, has published a series of essays in a booklet called What can Elected Mayors do for our Cities.
They include a paper by Guy Lodge, of the Institute of Public Policy Research, who said that city mayors would bridge the divide between national and local politics.
He wrote: “Mayors would not simply transform the look and feel of local politics but could have a transformative effect on Westminster too. Mayors who cut their teeth in Birmingham and elsewhere may later choose to enter national politics and would bring with them fresh perspectives that could make a big impact on national debate.
“And as we have seen in the case of Peter Soulsby and Sion Simon (two MPs who resigned their seats to fight for the mayoralty of Leicester and Birmingham respectively) the office of mayor might also attract national politicians back to their localities – a migration that is simply inconceivable under the current council leader model.
“In short, mayors in each of our major cities would represent a concrete move towards a more plural and layered polity.”
But a number of contributors to the booklet warned that city mayors will need powers over a wider “city region” in order to be effective.
So-called metro mayors would be able to influence housing, transport and economic growth while a mayor whose authority was limited to a city such as Birmingham might struggle, it was claimed.
Andrew Carter of the Centre for Cities, said city mayors should play a major role on regional bodies including chairing the integrated transport authority, such as West Midlands authority Centro.