EU Migration Commissioner Dimitris Avramopoulos | BERND VON JUTRCZENKA/EPA Council lawyers: Austria’s refugee cap not illegal Legal service opinion contradicts Commission on Vienna’s migration stance.

The EU Council of Ministers' legal team has refuted claims by the European Commission that Austria cannot impose a cap on the number of refugees it will accept.

In an oral opinion provided Wednesday at the regular meeting of EU ambassadors, the Council's legal service said that "in principle" imposing a cap is not contrary to international law, and much depends on whether countries provide reasonable reception conditions, several sources told POLITICO.

The opinion, which was given after a request from Greece, contradicts the Commission's earlier claim that capping the number of asylum seekers in the way Austria did would be "plainly incompatible" with international law.

A diplomatic source said the opinion of the Council's legal service does not yet mean the Council believes Austria is right, but that the question depended on several factors including the way refugees are received.

But to say Austria is in breach of international law is not correct, the source said, explaining the legal service's thinking. However another diplomat argued it is unlikely that Vienna will press its case just a few days before a summit of EU leaders that is considered crucial to show that Europe is still united on migration.

The move by the Council could spark a conflict between the two EU institutions on one of the key issues of the migration crisis.

Vienna's decision in late January to impose an "upper limit" triggered an exchange of letters between the Austrian government and the Commission, and a tug-of-war over the legality of the move.

Annual and daily limits “would be plainly incompatible with Austria's obligation under European and international law,” Dimitris Avramopoulos, the European Commission for migration, wrote to Austrian Interior Minister Johanna Mikl-Leitner on February 18. The Commission fears the decision could trigger a domino effect of similar measures across Europe.

Vienna contested the Commission's claims, saying its lawyers have a different opinion. It implemented a cap of 3,200 refugees per day, with 80 asylum claims a day to be processed, a drop of 20 percent on 2015 numbers, Mikl-Leitner told reporters on the day of the announcement, February 17.

A spokesperson for the European Commission said the institution was unaware of the Council legal opinion.

Hans von der Burchard contributed to this article.