Opinion polls in Britain are still divided over whether voters will choose to leave the European Union.

According to a weekly online poll by opinion poll firm ICM, 45 percent of voters were in favor of Brexit against 44 percent who believe Britain should remain in the 28-member bloc. The latest survey was weighted to take into account the likelihood of respondents actually voting in the June 23 referendum. As the Brexit battle in Britain continues, economists are debating what will happen if Britain leaves the European Union.

No country has ever left the EU or its predecessor, the Common Market, since its inception some 60 years ago.

In Britain’s high-rolling financial district, worries over Britain leaving the EU are at their height. With earnings making up to 10 percent of the UK economy, it is feared the UK capital’s role as a global financial center could be undermined. A report from government economists has warned a Brexit would cost British families up to U.S.$6,000 a year.

“If we left the EU, we’d lose tens of billions of pounds in money for our public services, because our economy would be smaller and our families poorer,” said UK finance minister George Osborne.

Other research from the International Monetary Fund, the World Bank and the Organisation for Economic Cooperation and Development arrives at similar conclusions-quitting the EU would hit the UK populace in the pocket.

“The ‘Brexit tax’ would be a pure deadweight loss, a cost incurred with no economic benefit,” said OECD secretary general Angel Gurria.

Europe’s most powerful leader, German Chancellor Angela Merkel, says “UK don’t go” while, U.S. President Barack Obama, says there will be no special trade deals.

So the question is: why would British Prime Minister David Cameron risk a referendum if a global consensus is stacked against a UK exit?

The 'Out' campaigners say they want control of their borders.

“Ultimately, what this referendum is really all about is: should we be in control?” said UKIP leader Nigel Farage. And so popular became that message, the government proposed an 'in/out' referendum. The latest opinion polls suggest the result could go either way.