Spanish PM Mariano Rajoy has told his Bulgarian counterpart Boyko Borisov “in no uncertain terms” that he had a problem with the May 17 Western Balkans summit in Sofia and that he might not even attend if Pristina was participating, the Brussels-based portal Euractiv reports. Rajoy, whose country does not recognise Kosovo’s unilaterally declared independence, said he “could attend a dinner of EU member states the day before the Sofia summit, but for the next day, he said: ‘We have an important issue. Some speak of enlargement with countries which are not recognised, including by Spain. This causes us some worry,'” the report said. Rajoy and Borisov met on the sidelines of an EU summit on Friday.