Turkey’s President Recep Tayyip Erdogan has accused Germany of “Nazi practices”.
Mr Erdogan hit out on Sunday days after a local authority in south-west Germany prevented a Turkish minister from addressing a rally.
He said: “In Germany, they are not allowing our friends to speak. Let them do so. Do you think that by not allowing them to speak the votes in Germany will come out ‘no’ instead of ‘yes?’
“Germany, you don’t have anything to do with democracy. These current practices of yours are no different than the Nazi practices of the past.”
On Thursday, Turkey’s justice minister cancelled a meeting with his German counterpart after local authorities in the south-west of the country withdrew permission for him to use a venue to hold a rally near the French border. It was part of a campaign to get Turks in Germany to vote “yes” in the referendum.
There are about 1.4 million people in Germany who are eligible to vote in the Turkish referendum.
Julia Kloeckner, a deputy leader of Chancellor Angela Merkel’s Christian Democratic Union, told the German daily Bild that Erdogan’s Nazi comparison was “a new pinnacle of immoderation.”
“Mr Erdogan is reacting like a stubborn child who can’t get his own way,” she told the paper.
Austrian Chancellor Christian Kern, in an interview with the German newspaper Welt am Sonntag, said it is time to pull the plug on long-stalled moves to bring Turkey into the 28-nation EU.
“We shouldn’t just temporarily suspend the accession talks with Turkey but end them,” Kern said.
“We can’t continue to negotiate about membership with a country that has been steadily distancing itself for years, during ongoing access talks, from democratic standards and principles of the rule of law.”