"The mere possibility that disciplinary proceedings or measures could be taken against judges on account of the content of their judicial decisions undoubtedly creates a 'chilling effect' not only on those judges but also on other judges in the future."
The EU's highest court looks likelier to deal another blow to Poland's controversial judicial reforms.
In an opinion released on Thursday, Evgeni Tanchev, the European Court of Justice's advocate general, said the changes were "contrary to EU law".
The ECJ still has to rule on the case and won't necessarily follow Tanchev's view.
Brussels and Warsaw have been embroiled in a legal battle over Poland's reforms to the judiciary since they were introduced in 2017.
Poland says the reforms are necessary to make the judicial system more efficient but the EU says they weaken its independence.
Tanchev's latest opinion pertains to disciplinary measures the Polish government has rolled out against judges.
The EU has argued that it allows the government to exert political control over the judiciary by allowing judges to be subjected to disciplinary actions on the basis of their decisions.
In his opinion, Tanchev said the European Commission has demonstrated that the "disputed provisions do not guarantee the independence and impartiality of the Disciplinary Chamber" and are, therefore, "contrary to EU law."
"He observes that disciplinary action should be instituted against a judge for the most serious forms of professional misconduct, and not on account of the content of the judicial decisions generally involving the assessment of facts, the evaluation of evidence and the interpretation of the law.
"The mere possibility that disciplinary proceedings or measures could be taken against judges on account of the content of their judicial decisions undoubtedly creates a 'chilling effect' not only on those judges but also on other judges in the future, which is incompatible with judicial independence," the opinion reads.
The other EU vs Poland cases
In a separate opinion released last month, Tanchev also sided with Brussels over the creation of two new chambers of Poland's Supreme Court.
"A court chamber does not constitute an independent and impartial tribunal, within the meaning of EU law, when the objective conditions in which it was created, its characteristics as well as the manner of appointment of its members are capable of giving rise to legitimate doubts," Tanchev wrote then.
He flagged that Polish President Andrzej Duda had violated an order of the Supreme Administrative Court to appoint new judges — and done so without waiting for a decision on the CJEU on the matter — which he said was "a potentially flagrant breach of fundamental norms of national law."
A ruling is also expected on that case.
The ECJ has already decreed that a Polish law lowering the retirement age for ordinary and Supreme Court law was against EU law.
The reform allowed the government of the ultra-conservative Law and Justice (PiS) party to stack the courts with its own appointees. The National Council of the Judiciary chooses new appointees but PiS exerts control over it.
The Court said then that the change was "not justified by a legitimate objective and undermines the principle of the irremovability of judges, that principle being essential to their independence."
The case of the Ombudsman
The Commission has also said it is "following closely and with concern" the development relating to Polish Ombudsman Adam Bodnar.
Poland's Human Rights Commissioner, or Ombudsman, is an independent civil servant whose role is to defend individuals facing threats to their civil rights.
Bodnar has drawn the ire of PiS over the years by challenging their reforms to the judiciary as well as its anti-LGBT rhetoric. His term expired in September last year but parliament and senate — respectively controlled by PiS and the opposition — have so far failed to agree on a replacement.
PiS took the matter to the Constitutional Court — which is filled with PiS appointees — demanding that a law that allows Bodnar to remain in his role until a successor is chosen be scrapped. The court gave Bodnar three months to vacate his position last month.
The Constitutional Court is also expected to side with the government on May 13 when it hands out its ruling over whether Polish or European Union law has primacy in the country.
The government demanded the Constitutional Court look into the matter following the CJEU's March ruling that the new law regarding the appointment of judges to the Supreme Court went against EU law.