Turkish ties with Germany worsen Amid a sharp increase in tensions between Turkey and the EU, Berlin and Ankara summoned each other's ambassadors in tit-for-tat moves as fresh obstacles to the Turkish bid to join the bloc emerged. German Foreign Minister Guido Westerwelle called the envoy to his offices "due to remarks from Turkish officials toward Germany," a ministry spokesman said, leading Ankara to later threaten consequences over the row. Turkish European Union Affairs Minister Egemen Bagis had fumed on Thursday that German reluctance to open a new chapter in EU accession talks was linked to Chancellor Angela Merkel's "election campaign." "That is unacceptable," German spokesman Andreas Peschke said. These remarks met with great disbelief here. We will make our position abundantly clear. But Ankara immediately fired back, saying it was planning to send for the German envoy to get an "explanation" of the summons in Berlin, a Turkish diplomat said. Mr Bagis said on Friday evening that Turkey was "disappointed" by Berlin's attitude and "regretted" its move to summon the envoy. "We have been disappointed by Germany's stance of preventing the opening of this chapter to negotiations," he said. We feel that our sincerity makes it necessary for us to express our disappointment. "We also regret to note the intolerance and misinterpretation of our sincere reminders by our German friends, who unfairly criticise Turkey regarding the freedom of expression," he said. Earlier Mr Bagis warned that Germany would face consequences if Dr Merkel did not lift her resistance. "I hope she corrects the mistake she has made by Monday ... or this will lead to reactions," he said. Earlier last week he had urged that "Merkel should consider the benefit of some 4000 German businesses in Turkey." Mr Bagis had reacted angrily to news from Brussels on Thursday that EU member states failed to reach the necessary consensus on opening a new negotiating chapter with Turkey next week. Mr Bagis on Thursday had placed the blame squarely on Germany, the EU's top economy with the world's largest Turkish migrant community as well as Ankara's biggest trade partner. Diplomats said that Germany and the Netherlands expressed "reservations" at the closed-door talks between EU ambassadors. "If Merkel is looking for material for her election campaign, it should not be Turkey," Mr Bagis said. referring to the general election in Germany scheduled for September.