Croatia clashed with the European Union on Wednesday over its plan to create a protected zone in the Adriatic Sea to preserve fish stocks and limit pollution, according to Reuters. When the Croatian parliament decided to set up the zone, it agreed to exempt neighbouring Slovenia and Italy, both members of the bloc which Zagreb hopes to join in 2010. But Prime Minister Ivo Sanader, under pressure from the opposition and the powerful fishing lobby, signalled last week that he might go back on the agreement. An angry EU Commission urged Croatia in a strongly worded statement on Wednesday to keep its word. "It would be detrimental to Croatia's credibility as a reliable partner in the region if it came out now with a unilateral move by activating the zone," the Commission said. Sanader replied that Croatia had every right to proclaim the zone and accused the Commission's representative in Zagreb of overstepping his authority by questioning the legality of Croatia's actions. President Stjepan Mesic, visiting Brussels to lobby for Croatia's admission to the bloc, told Commission President Jose Manuel Barroso the fisheries issue was set to be resolved, but failed to win a commitment to an EU entry date. Instead, Barroso gave Mesic a veiled warning that Croatia had to work harder at meeting EU entry criteria. "Many reforms are needed to create a more open, competitive economy," he said at a news conferece. "It is now crucial to continue the reforms with full determination." Croatian political analyst Zeljko Trkanjec said the row over the fishing zone could backfire on Croatia's EU ambitions. "Croatia does have a right to proclaim the zone. The question is whether it is politically wise," he said. Zagreb has been making slow progress in negotiations with the Commission on issues such as state subsidies -- and fishing.