By Valentina Pop and Natalia Drozdiak 

BRUSSELS -- The European Union's executive on Wednesday gave Poland three months to alter its stance toward the country's top court, an issue over which the government in Warsaw has drawn sharp criticism from its Western allies.

The deadline is the second in a series of formal steps taken by the European Commission, the EU executive, as part of what it calls a "rule-of-law mechanism" triggered by what it considers attempts by the Polish government to politicize the country's Constitutional Tribunal and curb media freedoms.

"Despite the dialogue pursued with the Polish authorities since the beginning of the year, the Commission considers the main issues which threaten the rule of law in Poland have not been resolved," European Ccommission Vice President Frans Timmermans said when announcing the three-month deadline to solve the crisis.

Since winning a landslide parliamentary election in October, Poland's conservative Law and Justice government has rewritten the rules governing the Constitutional Tribunal and stopped publishing its rulings in the Official Journal. The government has also scrapped the appointments to the court made by the previous administration and installed its own judges, moves contested by the court, the opposition, and thousands of people who repeatedly took to the streets. The government accused its predecessor of trying to pack the court in its favor ahead of last October's parliamentary elections.

On Wednesday, the EU warned Poland that the country hasn't sufficiently addressed the commission's initial concerns around publishing and implementing judgments and swearing in judges.

Failure to meet the three-month deadline could lead to sanctions, including the possible suspension of Poland's voting rights. Other EU governments would need to approve the sanctions, however, and Hungarian Prime Minister Viktor Orban has already vowed to veto any move against Poland.

Poland's foreign ministry criticized the EU's action as "very premature" ahead of the entry into force of new laws on the Constitutional Court and accused the commission of not abiding by the EU principle of sincere cooperation with national governments.

The EU said it was recommending that Polish authorities publish and fully implement judgments of the constitutional tribunal, including on the nomination of judges. The commission also advised Poland to automatically publish all of the tribunal's future judgments.

"If the constitutional tribunal cannot exert its function because of intervention by the executive branch of government, or by the legislature, then we have a problem and that's the problem we're trying to address," said Mr. Timmermans.

Wednesday's move came after the commission in June issued a formal opinion criticizing Poland's actions, the first formal step in the process that could end in sanctions.

The Polish government has contested the commission's right to correct an EU member state's behavior through such a procedure, which it said isn't based on EU treaties.

In early July, the government rushed legislation through parliament to change the internal rules of the court in a bid to resolve the crisis ahead of the North Atlantic Treaty Organization summit it hosted this month. The legislation still needs to be signed by the country's president to enter into force.

However, opposition lawmakers said the changes were only cosmetic and would do little to end the crisis, which they say stems from a government agenda to remove checks and balances on its activities.

On the sidelines of the NATO summit, U.S. President Barack Obama expressed concern about Poland's actions, saying "more needs to be done" to safeguard the country's democratic institutions.

Criticism came also from the Council of Europe, an intergovernmental human-rights body, which in June released a report saying "the prolonged paralysis" of Poland's constitutional court "bears heavy consequences for the human-rights protection of all Polish citizens and prevents human-rights proofing of legislation."

The Polish government at the time complained about what it described as "a lack of symmetry and selectivity in the commission's report about the measures undertaken by the government."

Write to Valentina Pop at valentina.pop@wsj.com and Natalia Drozdiak at natalia.drozdiak@wsj.com

(END) Dow Jones Newswires

July 27, 2016 16:44 ET (20:44 GMT)