According to a recent survey, one in five Londoners would vote for London to become independent from the rest of the UK, with support strongest among young people.

With such regional disparities in wealth across the UK, "the reality is that London is a separate country," writes the Guardian's Larry Elliot. "Perhaps we should make it official".

An American working in the capital's financial district once described London as "a first-rate city with a second-rate country attached," so with less than a week to go until Scotland decides, could an independence movement be brewing further south?

Why would London want to become independent?

Simple economics. London contributes more in taxes than it receives in public spending, and Boris Johnson has long been calling for London to have greater fiscal powers, according to the Financial Times’s Brian Groom. Becoming independent would allow London to spend its money on its own projects and investments, rather than it being spread across the UK.

London has created ten times more private sector jobs than any other city since 2010 and according to the Office for National Statistics, the average London worker contributes 70 per cent more to the nation's national income than those in the rest of the country.

The effects of the recession weren't felt as severely in the capital; this is evident in the booming property market. "What recession?" they ask on the Tube. "What house price crash?" they chorus in Bayswater," remarks the Independent's Sean O'Grady.

If London became a separate state, it would have a GDP on par with Switzerland and Sweden.

How would it work?

Experts suggest that if London ever were to become independent, it could be modelled on existing city states such as Singapore. Its boundaries would roughly follow that of the M25, according to the Evening Standard's Simon Jenkins and could be policed by digital mapping with no need for borders.

What it would mean for the rest of the UK

It would cause a major shift in the UK economy from one formerly focused on the financial sector to one with more emphasis on manufacturing, according to the BBC's former economics editor Sally Sanders.

She argues that an independent London would be just as beneficial for the rest of the UK. "As well as subsidising the rest of the country, London's very success was also holding it back," she points out.

"As an independent city state, London would have a higher exchange rate and higher borrowing costs. The rest of the country would, by contrast, get a competitive boost," according to the Guardian’s Larry Elliott.

It would also result in the decentralisation of government, giving local governments an alternative to adopting Westminster's "one-size-fits-all" policies.

And most importantly it would mean greater investment outside the capital, particularly in neglected sectors such as transport.

Will it ever happen?

Probably not. "This is, of course, fantasy," writes the FT’s Brian Groom. Unlike Scotland, London has no separatist movement."

Indeed, why would the UK give up its "goose that lays so many golden eggs"? asks Sanders.