Britain will veto plans for a European Union (EU) army as long as it remains a member of the union, the Defence Secretary has said.

Speaking after it emerged that some European nations, mainly France and Germany, wanted to create a “common military force” that would likely rival Nato.

EU leaders, minus Britain, are meeting in the Slovakian capital of Bratislava to discuss the way forward for the bloc after Britain. One of the documents discussed mentioned plans for the military force that will be put before the Commission in December before being agreed by June next year.

It also calls for the creation of a “single operational headquarters for all EU civilian and military missions to be more efficient and quicker to act”.

However, Britain’s Defence Secretary said that the UK will not accept any such move while it remains in the EU.

“That is not going to happen,” Sir Michael Fallon told The Times. “We are full members of the EU and we will go on resisting any attempt to set up a rival to Nato.”

“We have always been concerned about unnecessarily duplicating what we already have in Nato,” he added.

His words will likely enrage EU leaders, further complicating Britain’s withdrawal negotiations.

“Threatening to block what we want to do is not going to make an already difficult negotiation easier when Britain comes cap in hand on Brexit next year,” one EU diplomat said.

Sir Michael pledged, however, that Britain would remain committed to the security of the European continent have it had left the EU.

“We are not going to back out of our commitment to keeping Europe secure but we don’t want to see unnecessary bureaucracy at the EU level when we have got it in Nato,” he said.

The prospect of an EU army became a big issue during the referendum campaign, with Remain saying that such claims were scaremongering and that EU leaders had no plans to create a common defence force.

Britain has previously vetoed similar plans in 2011 and 2013.