German Foreign Minister Frank-Walter Steinmeier has said a "Brexit" would shake the entire EU. He made the comments at a news conference with his French counterpart Jean-Marc Ayrault.

"I think we both are able to say we wish that the majority of Britain makes the right decision. And the right decision from our point of view can only be to stay in the EU. I would like to add, Europe would be missing many things, which we are perhaps not aware of every day at the moment. But there would be a lot missing if Britain decides to leave. I hope it does not come to this and that the people campaigning for Britain to stay in the European Union will succeed in the end."

"One thing you can say with certainty: If Britain votes to leave the European Union, it would not just go on 28 minus one, but it would shake the European Union and it would require a concerted effort to ensure its stability and that a very successful process of integration lasting for decades doesn't turn into disintegration," he said.