Much as I would have liked to respond factually and truthfully to each and every piece of misinformation spread by the Brexit campaign, it was important that I stayed out of the domestic political debate. It was David Cameron's task to win the UK referendum, not ours.

The European Union has decades of experience in overcoming crises and has always emerged stronger after.

I have always considered it to be a minor miracle that after the war, people in Europe's border regions were able to forget everything and, in accordance with the slogan "Never Again War," develop a program that still works today.

My friendship with Martin [Schulz], by contrast, is completely different in that it goes far beyond politics.

Between now and then, after 43 years of European marriage, the whole body of legislation will therefore have to be disentangled. That entails a whole range of specific and very complex questions: what will be the future legal status of the millions of EU citizens in the UK and the millions of Britons on the continent?

In politics, there are different categories of friendship. My friendship with Greek Prime Minister Alexis Tsipras, for example .

I am for secret, dark debates.