The court of first instance asked the Polish Supreme Court if the decision issued under Art. 15 par. 1 letter a of the Brussels IIa Regulation can be challenged. According to this article, the court which has jurisdiction may, under certain conditions, request a court of another Member State to assume jurisdiction. The Polish Supreme Court emphasised that Brussels IIa Regulation does not regulate this issue. With reference to the above the national provisions shall be applied. The Polish Supreme Court had analysed provisions of the Polish Code of Civil Procedure and pointed out that the decision issued under Art. 15 par. 1 letter a of Brussels IIa Regulation cannot be challenged. However, the Polish Supreme Court stated that the decision issued under Art. 15 par. 5 of the Brussels IIa Regulation can be challenged.