The UK would become an isolated trading post with no more significance in the world than Guernsey if it votes to leave the EU, France’s economy minister has warned.
Emmanuel Macron was speaking as campaigning in the UK referendum remained suspended on Saturday following the killing of Labour MP Jo Cox in her West Yorkshire constituency.
The economy and immigration have dominated the arguments ahead of the key vote on Thursday.
Leave campaigners have claimed the nation would thrive outside the EU, but the Treasury said the UK would suffer a recession if it quits the 28-nation bloc.
Guernsey is a British Crown dependency and one of the Channel Islands.
Mr Macron told Le Monde: “Leaving the EU would mean the ‘Guernseyfication’ 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 also said the EU would also have to send “a very firm message and timetable” to the UK in the event of Brexit.
Mr Macron said: “In the interests of the EU, we can’t leave any margin of ambiguity or let too much time go by. You’re either in or you’re out.”
The minister went on to say the referendum, whatever the outcome, would force the EU to work at avoiding a possible “contamination” effect in other countries that could be tempted to leave the bloc.
Meanwhile, the International Monetary Fund has said Britain need not suffer a recession if it leaves the European Union.
The IMF said the UK economy would be comparatively weaker if it left the EU but under its “limited” scenario – in which Britain stayed in the European Economic Area, the group that includes Norway – growth would slip from 2.2% to 1.4% next year.
The drop is significantly smaller than that forecast by the Treasury.
However, the IMF added that under an “adverse” scenario, in which the UK left the EU and failed to seal a Norway-style deal, having to fall back on World Trade Organisation rules, the UK would suffer a recession in 2017 with the economy shrinking by 0.8%.