The rise of Eurosceptic parties like the UK Independence Party is a "worrying development" for the European Union that could put peace at risk, the German foreign minister has warned.
In a stark warning against against "nationalism," Frank-Walter Steinmeier said parties like Ukip, Germany’s AfD, Jobbik in Hungary and the French Front National could destabilise the cooperation that has kept the continent at peace.
Speaking on his first visit to London since being appointed in December, he warned that calls for Britain to exit the EU could have "dangers" – emphasising the importance of close ties during the run-up to the 1914-18 war.
Instead of moving further apart, European countries should work together, he said, to avoid any risk of conflict.
“History before the First World War was a history of not talking to each other, of nationalisms which could no longer be [tamed] by reason,” Mr Steinmeier said.
“These dangers have to be forever banned.”
Mr Steinmeier acknowledged that Germany may back David Cameron's pledge to change certain EU treaties, but suggested that Germany and Britain were not “pulling in exactly the same direction”.
He warned politicians, including Tory Eurosceptics, not to "backtrack" on what had been achieved through European integration.
"You have got Eurosceptics getting together in parties, getting more public attention, and while Europe is in a crisis it doesn't make our work any easier," he said.
"The European Union is one of the reasons for peace, even though our interests may have been different, even in spite of our different histories before agreeing on European cooperation.
"Despite the wounds we have inflicted on each other, we have managed to get together - politically - in this part of the world. We have convinced people, we have learned to deal with different opinions and that is civilising progress which cannot be questioned or challenged."