Head of foreign policy in the EU, Federica Mogherini, has reportedly spent 18 months preparing the defence document to be discussed by European leaders at a summit on June 28.
Mr Fox told The Telegraph: “Those of us who have always warned about Europe’s defence ambitions have always been told not to worry, but step-by-step that ever closer union is becoming a reality. We cannot afford to be conned in this referendum as we were conned in 1975.
“The best way to protect ourselves is to stay close to the US. The US defence budget is bigger than the next 11 countries in the world put together. Europe’s defence intentions are a dangerous fantasy and risk cutting us off from our closest and most powerful ally.
“We’re always told not to worry about the next integration and then it happens. We’ve been too often conned before and we must not be conned again.”
Andrew Bridgen, the Tory MP for North West Leicestershire, said: “This is the way the EU operates. The people were deceived about the aims of the EU in 1975 and they’re being deceived again today. For the security of our country we must vote to leave the EU.
“This blows out of the water the Prime Minister’s claim that we’re being excluded from ever closer union. Voters are being hoodwinked once again.”