“It might take some time but the only possible answer to these challenges is more Europe and a more political Europe,” he told Euractiv.
Robert Oxley, spokesman for the Vote Leave referendum campaign group, said: “Sadly there appears to be no limits to what EU advocates will try and exploit to further their goals of greater political integration.
“In any crisis the EU has only one response, more power and money for Brussels. If we vote ‘remain’ we can expect many more power grabs.
“That’s why it is safer to Vote Leave and spend the £350million we hand to Brussels every week on our priorities, not theirs.”