LONDON - British Prime Minister Theresa May is scheduled to visit Poland on Thursday, a day after the European Union (EU) launched unprecedented action against the country for a "serious breach" of its values, which could ultimately lead to Warsaw being stripped of its voting rights in Brussels.

May will travel to Warsaw as part of a landmark diplomacy drive centered on defense and security, as well as economic cooperation, accompanied by her most senior cabinet ministers.

As the prime minister is flying to Warsaw for crucial talks on Brexit with Mateusz Morawiecki, who took over at the head of the Polish government last week, she will personally raise concerns about Poland's judicial reforms, which was criticized by the EU as an anti-democratic threat to the country's rule of law, when she meets the new Polish prime minister.

"We place great importance on the respect for the rule of law and we expect all our partners to abide by international norms and standards," May's spokesman told reporters.

"The prime minister will raise her concerns with the prime minister when they meet tomorrow," said the spokesman.

The Thursday visit is seen as a test of the UK's commitment to the EU's liberal, democratic values and future relations with Europe.

European commissioners have recommended EU member states issue a formal warning to Poland under the Article 7 procedure, which has never before been used, warning Poland's government was putting fundamental democratic values at risk.

Thus far, the UK has remained neutral in the growing rift between Poland's hardline right-wing government and the EU, concerned about the optics of Brussels appearing to interfere with a country's domestic affairs.

The stakes for May's upcoming visit rose dramatically on Wednesday as the EU launched unprecedented disciplinary action against Poland over controversial reforms.

The Polish lower parliament passed the National Judicial Council reform bill and the Supreme Court reform bill earlier this month.

The judicial reforms have caused many controversies among Polish citizens and among foreign institutions as well. The reforms include changes in the electoral system of the members of National Council of the Judiciary and Supreme Court judges' retirement.

On Wednesday, the EU launched what has been dubbed the "nuclear option" by invoking Article 7 of the its treaties, a process that could see Poland's voting rights in Europe suspended.

Brussels warned Wednesday that "the rule of law is under threat" in Poland and accused the government of a "naked abuse of political power."