In an escalating dispute over the election campaigns for Turkey's controversial referendum, German Chancellor Angela Merkel called on Monday for calm after Turkish President Recep Tayyip Erdogan on Monday after he likened a cancellation of several rallies for German-Turks to "Nazi practices."

"It's not really possible to seriously comment on such misguided statements," Merkel said of the comparison. "You certainly can't justify them - not even during the election campaign for a referendum on introducing a presidential system in Turkey." 

"What makes it really serious - and in my opinion even rather sad - is that Nazi comparisons only ever lead to one thing, namely that the incomprehensible suffering of the victims of National Socialism is cheapened. And that's why such statements automatically disqualify themselves," Merkel said, taking a similar line to her spokesman, Steffen Seibert, who also urged calm in a debate with an "important" ally.

While encouraging Turkey to "talk openly and critically," Merkel's office sought, however, to draw a line under the latest dispute, saying that the two countries should "remember the special meaning of our close relationship and let cool heads prevail."

'Absolutely unacceptable'

Hours earlier, in an interview with German broadcaster ARD, chief of staff at the chancellery Peter Altmaier, of the Christian Democrats (CDU), described the comparison as "absolutely unacceptable."

"The government will also make this very clear" to Turkey, Altmaier said, adding that "there is absolutely no reason to allow ourselves to be reproached over this."

'Nazi practices of the past'

Speaking at a women's rally in Istanbul on Sunday, Erdogan said Germany wasn't "even close to democracy," claiming that the country's practices "are not different from the Nazi practices of the past."

"I thought it had been a long time since Germany left [Nazi practices]. We are mistaken," he added.

Erdogan also warned Berlin not to stop him speaking in Germany if he wanted to. 

"If you don't let me in, or if you don't let me speak, I will make the whole world rise up," he said.

'Absurd, disgraceful and outlandish'

German Justice Minister and Social Democrat (SPD) Heiko Maas responded on Sunday, telling broadcaster ARD that Erdogan's comments were "absurd, disgraceful and outlandish" and designed to provoke a reaction from Berlin.

"We have to take care that we don't let ourselves be provoked, he said. 

Maas warned against breaking diplomatic ties or banning Erdogan from visiting Germany, claiming that such moves would "play straight into the arms of [Russian President Vladimir] Putin, which no one wants."

Meanwhile, German Foreign Minister Sigmar Gabriel (SPD) told the "Bild am Sonntag" newspaper that although Germany values freedom of expression, whoever speaks here "must respect our rules."

Gökay Sofuoglu, the head of the Turkish Community in Germany (TGD), also criticized Erdogan, describing the Turkish leader's comments as a "derailment."

"Erdogan has gone a step too far," Sofuoglu told regional broadcaster NDR on Monday. 

Controversial referendum

The accusations from Erdogan followed several high-profile Turkish politicians being denied the right to attend rallies in Germany in the run-up to a controversial referendum on April 16 in which some 1.4 million Turks living in Germany are eligible to vote.

A "yes" vote would expand Erdogan's powers as president, with critics warning that the new presidential system would cement a one-man rule in the country.

Local authorities in several towns and cities had denied permission for the rallies to take place citing capacity and security concerns.

#FreeDeniz

Prior to Erdogan's accusations, German-Turkish relations had already taken a huge downturn in recent weeks following the arrest of German-Turkish journalist Deniz Yucel.

Yucel, a journalist for the German newspaper "Die Welt," was detained by Turkish authorities on February 14, making him the first German reporter to be detained in Turkey as part of Erdogan's wide-scale crackdown on press freedom.

The 43-year-old, who has penned several articles critical of the Turkish government's treatment of ethnic Kurds, has been in jail ever since, pending his trial for alleged terrorism propaganda.

His arrest prompted public demonstrations and uproar among politicians and fellow journalists, with Chancellor Angela Merkel describing his detainment as "bitter and disappointing."

In an attempt to diffuse tensions, Merkel spoke with Turkish Prime Minister Binali Yildirim on the phone on Saturday, only for Erdogan to lash out at Berlin hours later.

ksb/se (AFP, Reuters, dpa)