Germany's finance minister has said that no country in Europe would be able to cope with the challenges of the 21st century on its own.
European leaders have been ramping up their warnings about the consequences of the Leave campaign triumphing. They're concerned about the political and economic ramifications of Britain's ejection from the four-decade alliance.
Speaking at the IfW economic institute four days before Britons head to the polls, Wolfgang Schaeuble acknowledged that the the EU "is not perfect" but remains the best way to confront issues including the regulation of financial markets and global warning.
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"We should preserve and strengthen, not destroy it," he added.
EU referendum campaigning resumed today after a two day stoppage due to the tragic death of MP Jo Cox. The latest polls are suggesting that Britain's stance on EU membership is too close to call.
Prime minister David Cameron has warned there would be "no going back" if the UK votes to leave, arguing that re-joining the EU would require the UK to join the Eurozone and sign up to the Schengen borders agreement, and the surrender of rebates on Britain's contribution to the EU's budget.
It comes a day after French finance minister, Emmanuel Macron, said that Britain should be prepared for a "total exit" if it leaves the EU on 23 June, against suggestions that the UK would be able to adopt a Norway-style model following Brexit.
He added that if the UK did vote to go, it would be relegated to a tiny player on the world stage.
"Leaving the EU would mean the 'Guernsey-fication' of the UK, which would then be a little country on the world scale. It would isolate itself and become a trading post and arbitration place at Europe's border," he told the newspaper Le Monde.
German chancellor, Angela Merkel, warned earlier this week that the UK would lose full access to the single market if it decided to leave the EU. She said all aspects of the domestic market would "of course no longer be available for Britain".