The issue of migration took centre stage in the race to succeed Angela Merkel on Thursday after one of the front-runners called for the right to asylum to be changed in the German constitution.

Friedrich Merz, one of three contenders to succeed Mrs Merkel as leader of her Christian Democrat party (CDU) next month, called for the German constitution to be amended.

“I share your anger when there is talk of loss of control over migration,” Mr Merz told a party hustings on Wednesday night. “For a long time now I have that we should be prepared to talk openly about the right to asylum and whether it can continue if we seriously want a European migration and refugee policy.”

Mr Merz’s remarks attracted widespread criticsm and were swiftly condemned by his main rivals for the party leadership.

“The right to asylum was enshrined in the constituion for a good reason,” Annegret Kramp-Karrenbauer said. “The authors of the constitution chose their words carefully because of Germany’s historic responsibility for the persecution of the Jewish people. Jewish refugees were turned away at the borders of neutral countries and deported directly to Auschwitz.”

“The fundamental right to asylum for the persecuted comes against the backdrop of two world warsof great suffering and expulsions, and is a great achievement of our constitution,” Jens Spahn said. “The problem is that it is being exploited too often today, leading to uncontrolled migration.”