The commission has been following the situation in Poland closely since the Law and Justice (PiS) government was elected last year.

Soon after taking office, PiS passed a series of controversial laws. In particular, the government tried to end checks and balances on its power by refusing to recognise rulings by Poland’s constitutional court and trying to stack the same court with judges of its own choice.

Thursday saw pass a three month deadline given by the commission to Poland to address what it saw as ”systemic threats” to rule of law in the country.

Brussels would receive a formal answer, Szydlo told journalists in Warsaw.

”But our impression is that their recommendations are politically motivated. Poland is a democratic state. We will argue with with the commission and present our reasons and arguments,” she said.

”Personally, I cannot understand the commission is still dealing with Poland,” she added.

”Anything we do is based on the law, adopted by a parliamentary majority, in line with the Polish constitution.”

There was a need to rein in the EU executive, which was working beyond the mandate given to it by the EU treaties, Szydlo said, and warned that other countries, like the UK, could rebel against membership if Brussels did not stop.

”If the EU institutions keep working this way, they shouldn’t be surprised by the rise of crises and EU scepticism,” she said.

Warsaw’s collision course with Brussels could, in theory, end with sanctions. But the procedure is unchartered territory.

It's the first time the commission has made use of the framework, which was established in 2014.

Commission spokesman Margaritis Schinas told Brussels journalists on Thursday to be patient.

”We haven't yet received Poland’s letter. What we will do next depends on the answer provided by Warsaw.”