The EC has already requested Slovenia to comply with Directive 2011/18/EU on railway interoperability. However, Slovenia has failed both to implement the necessary measures and to notify the EC.

"The European Union's legislation on railway interoperability aims to improve the competitiveness of the rail sector," the EC says. "It establishes a regulatory framework for the technical harmonisation of Europe's railways and removes technical and administrative barriers, for example by providing common authorisation processes for putting railway assets into service."

The EC says that by failing to implement the Directive national verification and certification bodies cannot apply the same legal framework, which in turn hinders the free movement of rail components and equipment within the EU.