One of Europe's top human rights officials says a new bill passed by Poland's parliament regulating the Constitutional Tribunal "poses a serious threat to the rule of law."

Nils Muiznieks, the Council of Europe Commissioner for Human Rights, expressed his concern Friday, a day after Polish lawmakers rushed through legislation in an attempt to address international concerns about the rule of law on the eve of a NATO summit in Warsaw.

Poland's ruling Law and Justice party has faced international criticism over appointments to the court and legislation passed in December that effectively prevents the court from acting as a check on government power.

The Council of Europe had urged Poland to reverse the disputed changes. But Muiznieks said the bill adopted Thursday "goes in the opposite direction."