Poland’s logging of the ancient Białowieża Forest breaks European Union nature protection laws, a senior EU judge said today, in the latest twist in the strained relationship between Warsaw and Brussels.

Poland had argued that the felling of parts of Europe's last remaining primeval forest, where 800 European bison, wolves and lynx roam across shaded clearings, was necessary as part of forest management. Some oak trees have grown for 450 years and reach 150 feet, towering over swamps dammed by beaver.

Today’s decision is a non-binding legal opinion ahead of a final European Court of Justice ruling. The Polish government said it would abide by the final judgement.

The blow comes hot on the heels of a European Court of Justice judgement against Poland for not taking in its share of migrants under the EU’s refugee relocation scheme.

The European Commission has also moved to strip Warsaw of its EU voting rights after the government pushed ahead with judicial reforms that Brussels insists violate the rule of law.

Last week, the commission floated the idea of making EU funding, vital for Poland’s poorer regions, conditional on member state behaviour. Warsaw is against the idea.

“Poland, as a rule of law state, respects the advocate general’s opinion,” said Environment Minister Henryk Kowalczyk, who will be in Brussels to meet the EU’s environment commissioner on Wednesday to discuss the forest.