A series of cancelled campaign rallies planned by Turkish politicians on German soil has incurred the wrath of Ankara, with President Recep Tayyip Erdogan accusing Germany on Sunday of "Nazi practices."
Officials in various German localities have called off planned events this week at which Turkish ministers were scheduled to rally support for an upcoming referendum that would greatly empower Erdogan and weaken parliament.
Around 1.4 million Turks living in Germany are eligible to vote in the referendum, which is set for April 16.
Incensed by the recent cancellations, Erdogan levelled strong criticism against Germany: "Your practices are no different to the Nazi practices in the past."
At an event organized by the Kadem women's organization, the Turkish president accused Germany of being undemocratic.
Meanwhile, Turkish Economy Minister Nihat Zeybekci plans to attend a rally in a Cologne hotel on Sunday to drum up support among expatriate Turks.
Two events to be attended by Zeybekci in Germany - one in Cologne's Porz district and the other in the nearby town of Frechen - were already called off before the weekend.
And on Thursday, a rally at which Justice Minister Bekir Bozdag was due to speak was cancelled in the town of Gaggenau, with local authorities citing security concerns and insisting that the move was not politically motivated. A bomb threat was later made against the town hall.
Zeybekci criticized the week's cancellations by German authorities ahead of his departure from the city of Denizli in western Turkey. "It is not possible to accept this," he said.
A spokesman for Cologne police said that officers were preparing for the event featuring Zeybekci.
The minister also plans to address a concert in the city of Leverkusen on Sunday, according to a list of planned events for Turkey's ruling Justice and Development Party (AKP).
As scorn from the Turkish side reached fever pitch, a police spokesman in Hamburg confirmed Sunday that another rally was planned, this time to be attended by Foreign Minister Mevlut Cavusoglu. It is scheduled to take place in the German port city on Tuesday.
The owner of the event hall in Hamburg said Cavusolgu would begin his speech at 6 pm (1700 GMT) and that 250 attendees had been confirmed.
There were calls by the citizens' wing of the Christian Democrats (CDU), the party of Chancellor Angela Merkel, on the city mayor to prevent the event from taking place by "all means possible."
The row comes as already-fraught tensions between Berlin and Ankara are being tested anew by Turkey's jailing of German-Turkish journalist Deniz Yucel, a correspondent for Die Welt newspaper, who faces charges including membership of a terrorist organization.
Yucel, who was remanded in pre-trial detention last week, is one of scores of journalists detained in Turkey as part of a crackdown in response to a failed coup attempt in July.
Under an ongoing state of emergency, the government has also shuttered dozens of news outlets and purged tens of thousands from the judiciary and civil service.
German politicians have voiced concern over Erdogan's increasingly authoritarian rule, while the Turkish government has hit back, claiming that Germany is siding with terrorists and repeatedly accusing the country of harbouring militants.
Germany has not been the only European country to push back against Turkish attempts to campaign abroad.
The Netherlands has banned a planned rally of Turks in Rotterdam later this week, and Austrian Chancellor Christian Kern on Sunday called for an EU-wide ban on all such campaigning.
