On May 26, 2016, Poland was referred to the European Union (EU) Court of Justice for establishing restrictions for certain imported biofuels and raw materials used for the production of biofuel. The EU's Renewable Energy Directive requires sustainable biofuels and their raw materials be treated equally by Member States regardless of origin. Polish law provides preferential treatment for fuel operators sourcing at least 70 percent of their biofuels from Polish manufacturers, and for biofuel production from raw materials originating in certain countries. Poland also lacks fuel requirements for hydrotreated vegetable oil (HVO), despite EU law preventing fuels from being marketed without the requirements. The European Commission first sent Poland a formal notice in February 2014, with Polish authorities disagreeing with the Commission's interpretation of the Renewable Energy Directive.