Federica Mogherini, head of foreign policy in the EU, has spent 18 months preparing a defence document for discussion by European leaders at a summit on June 28 John Vizcaino/Reuters

Steps towards creating a European army are being kept secret from British voters until the day after next month’s referendum.

The plans, drawn up by the EU’s foreign policy chief, foresee the development of new European military and operational structures, including a headquarters. They are supported by Germany and other countries as the first step towards an EU army.

Similar proposals were vetoed by Britain in 2011, although there are concerns that a loophole could allow nine states to group together and bypass opponents.

To prevent the policy paper leaking and derailing David Cameron’s campaign to keep Britain in the EU, the plans will not be sent to national governments until the day after Britons vote.

Until then the Global Strategy on Foreign and Security…