The European Union's executive has triggered proceedings against Poland which could lead to sanctions over its recent decisions involving the judiciary.

The triggering of Article 7 was widely expected, and EU Commissioner Frans Timmermans said "we are doing this for Poland, for Polish citizens" so they can rely on a fully independent judiciary in their nation - a key underpinning of EU principles.

Mr Timmermans said that despite the measure indicating that "the rule of law is under threat", he remained open to dialogue with Warsaw to remedy this abuse "of naked political power".

Polish justice minister Zbigniew Ziobro insisted that despite the EU measure, Poland will continue to "reform" its justice system.

Mr Ziobro, who co-authored the controversial reorganisation of the justice system and whose powers are strengthened by it, said he had received the news of the EU's procedure with "calm".

He said Poland needs to continue with reforms, and that Poland "will only be a significant EU member when it has a well-functioning justice system".

He insisted its provisions were drawn from justice systems of western EU members.