KARLSRUHE, Germany/BERLIN (Reuters) - Turkish government officials cannot invoke German constitutional rights in seeking to enter the country for political appearances, Germany’s Constitutional Court said on Friday.

Turkish President Tayyip Erdogan greets his supporters during a campaign meeting for the April 16 constitutional referendum, in Ankara, Turkey, March 7, 2017. Kayhan Ozer/Presidential Palace/Handout via REUTERS

The ruling was published as tensions escalate over the cancellation of Turkish rallies in Germany in support of an April 16 referendum that would give Turkish President Tayyip Erdogan sweeping new powers.

German Foreign Minister Sigmar Gabriel’s spokesman said he did not expect the ruling to change the government’s view about appearances by Turkish ministers, which were generally hosted by private organizations covered by German law.

However, he said Germany had made clear that it expected Turkish officials to respect German laws and abide by common rules of decency.

The ruling was issued in response to a complaint filed by a German citizen against a Feb. 18 appearance by Turkish Prime Minister Binali Yildirim in the town of Oberhausen.

The court rejected the complaint, saying the rights of the citizen were not violated. However, it said the Turkish head of state and other leaders could not claim German constitutional rights to enter Germany, or in justifying their speeches.

Turkish officials have given Germany a list of potential appearances by the Turkish sport and family ministers and other officials, but no formal request for Erdogan to visit Germany.

Erdogan, who survived an army attempt to topple him in July, argues that he needs more powers to avert the instability of past coalition governments. But rallies by Turkish officials backing the change are causing growing unease in Europe.

Some 83 percent of Germans think Turkish politicians should not be allowed to campaign in Germany for the referendum, while 15 percent think such appearances were acceptable, a poll by Forschungsgruppe Wahlen for broadcaster ZDF showed on Friday.

Martin Schulz, the Social Democratic Party (SPD) candidate seeking to unseat Merkel, told Bild newspaper that Erdogan, as president of an allied country, was welcome to visit, but internal Turkish conflicts should not be played out in Germany.

Yildirim spoke to thousands of Erdogan supporters in Oberhausen last month as part of a broad drive by the Turkish government to rally support among the 1.5 million Turkish citizens who are eligible to vote in the April 16 referendum.

Speeches planned by several other Turkish officials, including its justice and economy ministers, in other German towns were subsequently banned by local officials citing security concerns, drawing sharp criticism from Turkey.

Erdogan criticized the decisions, likening them to “fascist” tactics used during the Nazi era in a series of speeches that stunned German leaders.

“When Turkish government officials accuse us of Nazi tactics that is crossing a red line,” Schulz said. “That’s when a chancellor must say, ‘That’s enough.’”