Luxembourg over the non-implementation of the border arbitration award.

Slovenia claims that by refusing to implement the June 2017 border arbitration award, Croatia violates the principle of the rule of law. As a result, it undermines Slovenia's ability to implement EU law and violates Schengen rules and common fisheries rules. Croatia claims it had withdrawn from the arbitration process in 2015 and wants a bilateral agreement. Slovenia on the other hand, insists that the EU-sponsored arbitration decision must be honored.