Germany and Turkey summoned each other's ambassadors on Friday for tit-for-tat reproaches in an escalating row over Chancellor Angela Merkel's criticism of a crackdown on protesters in Turkey and her reluctance to see the country join the European Union. After Merkel said she was "appalled" by Ankara's response to the protests, a Turkish cabinet minister accused her on Thursday of blocking Turkey's accession to the EU because she was "looking for domestic political material for her elections". Berlin responded on Friday by summoning the Turkish envoy to the German foreign ministry - then Turkey retaliated. Many EU countries support the opening of more negotiations with Turkey next week on its long path to membership. They argue that Turkey, with its fast-growing economy, youthful population and its diplomatic clout, would benefit the EU. But Germany has criticised Prime Minister Tayyip Erdogan's forceful response to weeks of anti-government protests and appears to be refusing to agree to open a new negotiation area, potentially the first such step in three years. Merkel's conservatives reject Turkish EU membership in their platform for September's election, saying it would "overburden" the bloc because of the country's size and economy, though Merkel has stopped short of calling a halt to accession talks. "Neither the chancellor nor the government are questioning the accession process in any way. We are not talking about 'whether', just about 'how', to continue the accession process," said German deputy government spokesman Georg Streiter. Foreign ministry spokesman Andreas Peschke said the Turkish minister's comments were "unacceptable" and that Ankara's envoy to Berlin had been summoned for consultations in the early afternoon. Turkey reacted by summoning the German envoy to Ankara, with a senior Turkish official telling Reuters: "We want to convey our views on recent developments." Peschke said Turkish accession talks had been held up for unspecified "technical reasons" rather than concerns about the crackdown, adding that the Dutch shared the German view. Chapter 22 of the talks deals with regional politics. German Foreign Minister Guido Westerwelle said this week he would like to see discussion of the chapters 23 and 24 that deal with civil rights, freedom of the press and freedom of assembly. These have been blocked by other EU member states because of concerns about Turkey's record on human and civil rights.