Angela Merkel's Chief of Staff Eyes Ban on Turkish Campaigning in Germany

The German government will not rule out a ban on Turkish politicians campaigning in Germany, Chancellor Angela Merkel's chief of staff said in an interview published Wednesday amid an escalating row between Ankara and European countries.

Turkish President Tayyip Erdogan's drive to drum up support among Turks living abroad for an April 16 referendum to expand his powers has caused deep strains in ties between Ankara and Berlin and other European capitals.

"We will take a close look at what is responsible and what is not. An entry ban would be a last resort. But we reserve the right to do that," Peter Altmaier told the Funke Mediengruppe newspaper chain.

Emotions are running especially high after Germany banned several planned rallies by Turkish ministers, citing public security concerns. Erdogan has branded such bans "fascist," infuriating the German government. The Netherlands, similarly, has been labeled fascist for blocking a Turkish minister.

The small western German state of Saarland said Tuesday it was invoking its right to ban political activities that put at risk the peaceful coexistence of Germans and foreigners.

Altmaier said international law allowed all countries, including Germany, to ban the entry of foreign government officials, although this occurred only rarely.

"It's never happened in Germany, as far as I know," he said. "But the fact that Germany has not made full use of its options under international law is no 'free pass' for the future."

He said Germany continued to fight for democracy and freedom of the press, one reason it had allowed appearances by foreign politicians in Germany.

But he said Turkey's Nazi comparisons were unacceptable and highly problematic, and Germany would not allow Turkey to transfer its internal conflicts to German soil.

"Turkey is always concerned that the pride of its country is not injured. But Germany has its pride too," he said.

"Since its founding, the Federal Republic of Germany has been recognized around the world as a exemplary constitutional state .... We will not let that reputation be sullied by anyone, not even by Turkish politicians carrying out election campaigns at home."

Altmaier said declining travel by Europeans to Turkey should give Ankara pause. "Respect for freedom of the press, the rule of law and a separation of powers is also in Turkey's national interest," he said. "These developments are a cause of great concern to many people, including me personally."

German politicians have been highly critical of mass arrests and dismissals in Turkey since a failed military coup last July. Critics of Erdogan say wider powers being put to a referendum would erode political checks and balances, but Erdogan says the powers are essential to maintain stability in Turkey.

Berlin would continue to press for fair treatment of German-Turkish journalist Deniz Yucel, who was arrested in Ankara last month, and rejected as "absolutely baseless" Turkey's claim that Yucel was working as a German spy.