The recent election result means that we will have an in-out referendum on EU membership by 2017. It seems likely that David Cameron will not be politically strong enough to win a deal from the rest of Europe that he will be able to sell to his newly invigorated right wing. As a result he will not be able to recommend continued EU membership unambiguously to the country, and in those circumstances, and in the light of the election results, it seems quite possible that Britain as a whole will vote for exit.

Yet if it happens that vote will be far from uniform geographically. Like the results of this election, any vote in favour of British exit will be primarily a phenomenon based on rural, small town and suburban England and Wales. Scotland will by that point have presumably decided to decamp so will set its own European course.

As in the election, the EU referendum will present Britain's urban areas with a paradox - if exit happens, they will be taken for a political ride that reflects neither their cosmopolitan values nor their open economy interests. Nowhere is that more true of London - a cosmopolitan, liberal world city whose role as European financial services centre will be broken by British withdrawal. It seems time to propose that London becomes an independent City state which can insulate itself from the dominant illiberal and inward-looking politics elsewhere in Britain and continue to be a financial and socially open society at the heart of Europe.

Other cosmopolitan urban areas of Britain might like to follow suit.