Trump has a clear goal: the division of Europe and the destruction of the European domestic market. The fact that Brexit propagandist Nigel Farage was the first European he received in his tower speaks volumes. That is why we must strengthen the European domestic market and work even more closely together in Europe. That is absolutely compulsory for Germany.

Before we talk about further accessions, we have to consolidate the European Union internally. People are increasingly losing faith in the EU's effectiveness.

I find it surprising, however, that many German politicians generally oppose referendums, but then when it's an EU matter, they immediately scream for a plebiscite.

The principles of the SPD have remained the same for 150 years: democracy, human dignity, justice and inclusion. We will never change those principles.

We have committed ourselves to pursue joint policies, but then national governments say, "We aren't bound by that." That is a dramatic situation, because solidarity is a basic principle that cannot be had on an à la carte basis. If we have rules that nobody adheres to, then the community will break apart.

Now Europe are experiencing a wave of eroding solidarity, first of certain societies and then entire governments. At the same time, we have two giant new challenges to meet: the migration movement and terror. And then Great Britain is thinking about leaving the EU. That should suffice as a description.

Primary responsibility for Brexit lies with British conservatives, who took an entire continent hostage.