European Council President Donald Tusk warned today that if Britain votes to leaves the EU in next week's referendum, it could spell the "destruction" of Western political civilisation.
Beyond negative economic implications, a Brexit would trigger "first and foremost geopolitical" consequences, Tusk told German mass circulation daily Bild in an interview.
"Do you know why these consequences are so dangerous? Because in the long-term they are completely unpredictable," he said.
"As a historian, I am afraid this could in fact be the start of the process of the destruction of not only the EU but also of Western political civilisation," Tusk said.
In excerpts of the interview released yesterday, Tusk had said the process of negotiating a new relationship between Britain and the EU in case of Brexit could take up to seven years.
The process of dissolving all contractual ties between the bloc and Britain would itself already take two years, he said.
And more time would have to be factored in before a new relationship could be agreed upon, he said.
"Every single one of the 27 member states as well as the European parliament would have to approve the overall result. That would take at least five years, and I'm afraid, without any guarantee of success," added Tusk.
An online opinion poll for the Independent newspaper Friday showed the Brexit camp leading by ten percentage points ahead of the June 23 referendum.