Berlin said on Friday it wouldn't allow voting in Germany for any possible referendum on whether to reintroduce the death penalty in Turkey.
Tensions between Turkey and Germany soared ahead of last month's constitutional referendum. Berlin did not hide its stance on the referendum but rather opposed the campaign that changed Turkey's governance from a parliamentary system to a presidential one.
Turkish President Recep Tayyip Erdogan has spoken of reinstating the death penalty on several occasions. Germany and other European countries vehemently oppose execution in Turkey.
Chancellor Angela Merkel's spokesman, Steffen Seibert, said that "there is no obligation" for the German government to approve a request from a foreign country.
"It is politically inconceivable that we would agree to such a vote in Germany on a measure that clearly contradicts our constitution and European values," Seibert told reporters in Berlin. "I assume that we would use all legal means to prevent something like this."
The German government says that its permission is required for voting in foreign elections or referendums to take place at embassies, consulates or elsewhere on its territory.
There are around 1.4 million eligible Turkish voters in Germany and the April 16 referendum on a constitutional change backed by the governing AK Party won 63 percent of the votes cast in the European nation.
In comments published earlier Friday, Merkel's challenger in Germany's September 24 election took a similar line.
"If the Turkish government really held a referendum on the introduction of the death penalty, it must be clear that such a vote must not take place among Turks living in Germany," Martin Schulz told the weekly Der Spiegel.
"We cannot allow voting in Germany on an instrument that contradicts our values and our constitution."
Schulz's centre-left party is the junior partner in Merkel's current coalition government.