The president of the EU says euroscepticism leads to mercantilistic trade and foreign policy and eventually to war
Mr Van Rompuy linked hostility to the EU, and the idea that countries could leave the Union, to a revival of aggressive nationalism.
"We have together to fight the danger of a new Euroscepticism. This is no longer the monopoly of a few countries," he said. "In every member state, there are people who believe their country can survive alone in the globalised world. It is more than an illusion: it is a lie."
The controversial comments made on Tuesday come less than a fortnight after David Cameron, the Prime Minister, declared that he was a Eurosceptic after his gruelling Brussels summit battle to block a sharp increase in the EU budget at a time of national austerity.