The European Union's executive defended Tuesday its decision to investigate Poland for a possible breach of the bloc's fundamental values, hours before the European Parliament was due to debate controversial reforms by Warsaw.
Poland's conservative government, which took office in November, has come under fire for several measures that critics say are designed to strengthen its grip on the judiciary and the media.
The dispute has raised tensions between Warsaw and its European partners, at a time when unity is needed within the 28-member EU to address a host of challenges, including the bloc's migration crisis.
Last week, the European Commission launched an inquiry focusing on reforms to Poland's constitutional court and criticizing a recent law granting the government power over top appointments to the country's public broadcasters.
"The commission has a role to play as a guardian of the [EU's] treaties," spokesman Alexander Winterstein said Tuesday.
On Monday, EU President Donald Tusk - a Polish national - criticized the inquiry, saying he would have preferred the bloc's executive to pursue the matter by "other measures," following talks with the country's president, Andrzej Duda.
Later Tuesday, Polish Prime Minister Beata Szydlo was expected to defend her government's reform programme in a plenary debate with EU lawmakers.
Parliament President Martin Schulz said he expected a "lively" discussion, in comments last week.
He has come under fire in Poland for saying that Szydlo's government was conducting "Putin-style politics." But Schulz said Thursday that he had a "very polite" and "mutually very respectful" phone conversation with the premier.
The two were shown smiling and shaking hands as they met ahead of Tuesday's debate, in the French city of Strasbourg.
In Warsaw, meanwhile, opposition politician Ryszard Petru expressed hope in early elections, despite the absolute majority of Szydlo's Law and Justice (PiS) party.
He accused PiS party leader Jaroslaw Kaczynski of running a "dictatorship," in comments to the RMF broadcaster.