Germany warned Turkey on Monday against reinstating the death penalty, as it blasted "revolting scenes of caprice and revenge" in the wake of a failed coup attempt.
In strongly worded remarks, Chancellor Angela Merkel's spokesman Steffen Seibert told reporters that Berlin had grave questions about President Recep Tayyip Erdogan's response to the foiled military takeover.
After Erdogan said Sunday that Turkey would consider a return of capital punishment, Seibert said such a move "would mean the end of EU membership talks".
Seibert said the EU was a "community of laws and values" with which capital punishment was not compatible.
"Germany and the EU have a clear stance: we categorically oppose the death penalty. A country with the death penalty cannot be a member of the EU," he said.
He urged a proportionate response from the government in Ankara.
"In the first hours after the failed coup, we witnessed revolting scenes of caprice and revenge against soldiers on the streets," Seibert said. "That cannot be accepted."
Seibert reiterated that Germany "condemns" the attempted takeover but stressed that the response by the Turkish government needs to be "proportionate" and "based on the rule of law".
"In that context, we need to say clearly: it raises profound and worrisome questions when on the day after the coup attempt, 2,500 judges are removed from their posts," he said.
In the aftermath of Friday's failed coup, thousands of Erdogan supporters called for capital punishment to make a return.
"In democracies, decisions are made based on what the people say. I think our government will speak with the opposition and come to a decision," Erdogan said Sunday.
Turkey abolished the death penalty in 2004 under reforms aimed at obtaining European Union membership.
Reinstatement would create further issues between the EU and Ankara in the already stalled membership talks.
Germany has the largest ethnic Turkish community outside Turkey with some three million members.