The UK will vote on leaving the European Union next week, and the polls still show the two sides with similar levels of support.
European Council President Donald Tusk supports the UK remaining in the federation, and says that voting to leave could lead to the end of western civilization.
"Why is it so dangerous? Because no one can foresee what the long-term consequences would be," he told the German paper Bild. "As a historian I fear that Brexit could be the beginning of the destruction of not only the EU but also of western political civilization in its entirety."