But what would "Brexit" — a British exit from the 28-nation EU — look like? Eurosceptics argue that withdrawal would reverse immigration, save the taxpayer billions and free Britain from an economic burden. Europhiles counter that it would lead to deep economic uncertainty and cost thousands, possibly even millions, of jobs.

"Brexit" would pose a grave threat to the UK car industry and the City of London, and cause foreign investment to dry up, a report for the Centre for European Reform (CER) stated.

The Brexit Prize, referring to talk about a British exit, or "Brexit", from the EU, asks entrants to imagine that a referendum has resulted in an "Out" vote and the Government has triggered Article 50 of the Lisbon Treaty.

But as the Olympics head to the close, the possibility of a British exit from the European Union — or a 'Brexit' — is getting a serious airing in London financial circles.

Yet the chances of Britain leaving the EU in the next few years are higher than they have ever been. A Brixit looms for several reasons.