Europe's leaders have issued a passionate plea for Britain to remain in the European Union, fearing that "Brexit" could set off a disastrous chain of events at a time of existential crisis for the European Union.
Manuel Valls, the French prime minister, said the whole of European civilisation was under grave threat and the region must stick together in self-defence. He said the departure of the UK "would be a tragedy".
Mr Valls warned that the European system was alarmingly fragile. "Europe could lose its historical footing and the project could die quickly. Things could fall apart within months," he told the World Economic Forum in Davos.
"We are involved in a world war against terrorism. We're going to have to live with this threat for years," he said, insisting that Europe must go on the offensive to defeat Isil and jihadi forces in Libya, the African Sahel, and Syria.
Wolfgang Schaeuble, the German finance minister, implored the British people to vote yes to Europe in this year's referendum. "It would be a disaster otherwise," he said.
Political leaders in Berlin are deeply concerned that British withdrawal could change the balance of power and the internal chemistry of the EU, leaving Germany with an unwelcome hegemony that would strain the Franco-German partnership to breaking point.
Mr Schaeuble has warned in the past that if the EU is unable to stop one of its more prosperous members from walking out in frustration, hard-headed investors in Asia, the US, and around the world, will take it as evidence that the EU was in terminal decline.
'Room of dynamite'
Separately, Mr Schaeuble gave a strong hint that there can be no bail-out funding for Greece unless the International Monetary Fund agrees to take part. "It would be like walking into a room full of dynamite carrying a lighted candle," he said.
The IMF has refused to do so until there is debt relief on a sufficient scale to clear the way for recovery.
Enda Kenny, the Irish Taoiseach, played down earlier suggestions that Dublin is losing patience with Britain and will no longer try to keep the country in the EU "at any cost". He insisted that preventing Brexit is a strategic priority of the first order for Ireland.
"Ireland supports very strongly the fact that Britain should remain a central player in the European Union. The Union would be weaker without Britain. And obviously it would have implications for Ireland were Britain to leave," he said.
Mr Kenny warned earlier this month that Brexit could lead to border controls between the Republic and Northern Ireland, while a report by the Dublin think tank ESRI said the economic fall-out from British withdrawal would be disastrous for Ireland.
Mark Rutte, the Dutch premier, sought to soothe fears that the EU is trying to dictate terms to the UK. "David Cameron has a lot of credibility and influence. I am fairly optimistic we will get to a positive outcome in February," he said.
In truth, the Brexit dispute is viewed as a deeply-irritating distraction at a moment when Europe is grappling with multiple crises.
Over 35,000 migrants crossed into the EU in the first three weeks of January, and this is expected to surge once the spring thaw arrives. Mr Rutte said there must be an end to the open-door policy, and a return to the Dublin regulations where refugees are held in the first country of entry. "We need to get a grip on this issue in the next six to eight weeks," he said.
That prompted a retort from Greek premier Alexis Tsipras, sitting on the same panel. "All European countries must share the burden," he said.
The Telegraph London