ANKARA - Turkish Prime Minister Binali Yildirim called a phone call Saturday with German Chancellor Angela Merkel “productive”, following a row over rallies cancelled in Germany ahead of Turkey’s key vote on presidential powers.

Ankara and Berlin have been locked in acrimony over the last few days after German towns blocked events where Turkish ministers sought to address Turks living there about the April 16 referendum.

Turkish voters will be asked whether to approve constitutional changes to create an executive presidency giving more power to the head of state.

Yildirim spoke with Merkel by telephone on Saturday and described their conversation as “good and productive” after ministers hit back at Berlin over its reaction. He told reporters that the foreign ministers of the two countries would meet next week to discuss the issue.

Earlier in the day, Turkish Justice Minister Bekir Bozdag said: “Mrs Merkel says they (the Germans) respect freedom of expression; the foreign minister says we have no impact on this decision, but if you look carefully at both, they do not criticise the decision” of the towns.

“They do not say the decision taken by the authorities is wrong,” the minister added, speaking to reporters in the central province of Yozgat. Merkel said on Friday that the decision was “taken by municipalities, and as a matter of principle, we apply freedom of expression in Germany”.

In the run-up to the vote, trips by Turkish politicians to Germany have come under heavy criticism as the government seeks a “Yes” vote from the huge community of Turkish expatriates.

Bozdag was due to speak at a rally on Thursday in Gaggenau in western Germany but it was cancelled, while Cologne city authorities also withdrew permission for a hall to be used for a speech by Turkish Economy Minister Nihat Zeybekci.

A third town, Frechen on the outskirts of Cologne, scrapped a rally that had been scheduled for Sunday.

“This is an unfortunate decision against democracy, freedoms,” Yildirim told a rally earlier Saturday in the central Turkish province of Kirsehir.

“I ask, not allowing the Turkish justice minister to speak, does it adhere or not to German human rights, Mrs Merkel?” Bozdag declared.

Germany is home to the biggest population of Turks outside Turkey with around three million in the country of Turkish origin, the legacy of a massive “guest worker” programme in the 1960s-70s.

The turmoil in relations between Berlin and Ankara has been ongoing since Germany criticised the large-scale crackdown on suspected coup-plotters and those alleged to have links to Kurdish militants following last July’s failed coup.

And ties have worsened after the formal arrest of Turkish-German Die Welt journalist Deniz Yucel on Monday who is accused of “terrorist propaganda”.

Turkish pre-vote rallies have also come under scrutiny in the Netherlands where Dutch Prime Minister Mark Rutte said a planned pro-Erdogan rally in Rotterdam on March 11 would be “undesirable”.

“We believe that the Dutch public space is not the place to conduct another country’s political campaign,” Rutte said in a statement on Facebook on Friday.

That drew an angry response from Turkish Foreign Minister Mevlut Cavusoglu on Saturday.

“What do you mean we can’t (campaign)? Where is democracy? Where are freedoms? Where is freedom of expression? Where is freedom of assembly?”

Cavusoglu insisted that “none of you can stop us”, adding: “We will go where we want to go, we will meet with our citizens and we will have our meetings.”

When asked about Rutte’s comments, Bozdag said politicians in Europe were being anti-Turkey in their quest for votes ahead of elections - the Dutch vote on March 15 - which he said was a “big mistake”.

The justice minister accused “several” European Union countries of being against changing Turkey’s governing system because they did not want it to be a strong and stable nation.