Forget Brexit. A bigger problem for the European Union lies in Poland, where a protracted conflict is becoming more and more likely. And Brussels is reportedly becoming increasingly worried.

Poland’s leader, Jaroslaw Kaczynski, has hand-picked his second prime minister in two years, opting last week for western-educated Finance Minister Mateusz Morawiecki as he seeks to rejuvenate the economy after revamping the judicial system.

As reported by Bloomberg, Morawiecki is another Kaczynski acolyte who has backed the increasingly authoritarian Law & Justice party’s push to seize more control of the courts, a plan condemned by the European Parliament and European Commission.

Concerns about the shift in Poland triggered calls to limit access to EU funds for countries disrespecting the democratic rule of law. The issue has been raised by EU member states, including Germany, France and the Nordic states.

According to Bloomberg, the risk for the EU is that a country that was so key to its post-Cold War political and economic integration shifts closer to becoming a rogue member under Kaczynski, 68, a critic of Poland’s deal to enter the bloc in 2004. A breakdown would undermine the European project in arguably a more symbolic way than traditionally lukewarm Britain’s pending departure.

So far, the cost of Kaczynski’s stance has largely been counted in lost influence within the 28-nation bloc, which lacks the unanimity needed to up the ante and strip the Polish government of its voting rights at EU summits.

There’s been no hit to the €229bn in aid granted to Poland through 2022 and used for everything from new airports to sewage pipes.

This could soon change. French President Emmanuel Macron said last month that Poland could pay a price if it continues to defy the EU on justice.

Meanwhile, the Polish parliament is finalising legislation to revamp the Supreme Court and Judicial Council, a powerful body that chooses which judges get promoted. Passage of the bills constitutes the removal of the “last fuses” on Poland’s democracy, according to Adam Bodnar, the country’s commissioner for human rights.

According to Bloomberg, some Polish politicians have been privately telling their EU partners that if bashing the Law & Justice government doesn’t stop, Poles will turn against the EU and nationalist forces will be emboldened.

A reduction in funds that Poland receives from the EU would help shift public opinion against the bloc, Marcin Matczak, a law professor at Warsaw University, was quoted as saying by Bloomberg.

“Hostility towards the EU is part of Law & Justice’s DNA, and if it was up to the party, Poland would leave the bloc,” said Matczak. “But Kaczynski knows he can’t do that because Poles are benefiting from EU membership. Hence, the party slowly builds a negative attitude towards EU – while declaring that Poland has no intention of leaving.”