David Cameron risks losing the EU referendum as voters blame Brussels for a migration crisis driving the continent to its most perilous days since the eve of the First World War, one of its senior figures warned yesterday.

Donald Tusk, European Council president, said that negotiations over the prime minister’s reform demands were “very fragile”. European leaders will meet at a summit next week to try to finalise Britain’s new terms of membership of the EU.

“The migration crisis is the worst political context for this referendum, I have no doubt, because it is so easy to blame the EU as a whole, the EU institutions, other Europe countries for this migration crisis,” Mr Tusk said in Brussels. “And I am afraid that this is