Polish President Andrzej Duda on Tuesday signed into law a bill giving the justice minister the power to hire and fire the heads of ordinary courts, one of three bills passed by parliament as part of the Law and Justice (PiS) party's flagship judicial reform plan.

On Monday, Duda announced that he would veto the other two bills, which aimed to give the government powers to determine the makeup of the Supreme Court.

"The president has signed the July 12 bill," the deputy head of the president's office was quoted as saying on the presidential website.

The bill allows the justice minister to hire and fire the senior judges who head ordinary courts, a measure that the PiS says is needed to make the judiciary more accountable to the people and make a creaking system more efficient. Critics say it will compromise the independence of judges.

The conservative, euroskeptic PiS's plans to reform the judiciary have brought tens of thousands of protesters onto the streets in cities across Poland, and raised concerns in the European Union and Washington. Opposition parties welcomed Duda's veto of two of the bills but urged him also to block the third.

Duda is to present his own alternative proposals in the next two months for the bills he vetoed.