The European Commission on Saturday launched infringement procedure against Poland over a judiciary law which the EU said falls foul of gender equality in employment and undermines judicial independence.

In the wake of the publication of the Law on the Ordinary Courts Organization on Friday, the Commission sent a "letter of formal notice" to Warsaw, putting the infringement procedure in motion, said a statement from the Commission.

The Polish government is given one month to reply to the letter.

The key concern the Commission raised in the letter is that the law introduces a different retirement age for female judges (60 years) and male judges (65 years), thus in violation of gender equality, a principle enshrined in Article 157 of Treaty on the Functioning of the EU.

The Commission also frowned on the discretionary power invested in Polish justice minister to dismiss and appoint court presidents, saying the independence of Polish courts will be undermined.

If the Commission is not satisfied by Poland's reply to the letter, or get no rely within the one-month deadline, the Commission will issue a "Reasoned Opinion", the second stage of the infringement procedure, said the statement.

Vice President of the European Commission Frans Timmermans on Wednesday warned that the Commission would immediately launch infringement procedure once Poland publishes the Law on the Ordinary Courts Organization.

The EU has been at loggerheads with Poland over four controversial bills, two of which have been adopted by the Polish parliament but vetoed by President Andrzej Duda.

The Law on the Ordinary Courts Organization was pushed through by the Polish parliament earlier this month and signed by Duda on July 25.

The other one -- the Law on the National School of Judiciary -- has already been published and in force.

The Polish government's judicial reform, creeping since late 2015 when the Law and Justice Party took power, has drawn criticism from the EU, which has sent Warsaw several warnings since then.