(Bloomberg) -- Poland is stepping up its confrontation with fellow European Union member Germany by creating an institute to advance reparations claims for atrocities committed during World War II.

Since taking power in 2015, the nationalist Law & Justice party has demanded that Germany pay for the damage committed during 1939-1945 Nazi occupation of Poland, during which about 6 million Poles -- half of them Jews -- were killed. 

A special parliamentary group has calculated the damages to Poland, though the assessment isn’t available to the public, according to the assembly’s website on Monday. A preliminary report published in 2019 put the bill at $850 billion, or nearly two years of Poland’s current economic output.

The head of the legislative group, Law & Justice parliamentarian Arkadiusz Mularczyk, said Poland would create a “War Losses Institute” to carry out further work on the impact of Nazi and subsequent Soviet occupation, after the war.

“This is another important step in shaping Polish historical awareness!” Mularczyk said on Twitter. 

The announcement comes during a standoff between Warsaw and Brussels over Poland’s adherence to EU democratic standards that’s put 36 billion euros ($41 billion) in aid on ice.

It also coincides with a changing of the guard in Germany, where outgoing Chancellor Angela Merkel has remained an advocate of Poland, even as other EU states call for harsher punishment. Germany is Poland’s biggest trading partner and a crucial voice in EU deliberations.

Unlike western European nations that settled World War II claims in the decades following the conflict, Poland signed its postwar border treaty with Germany only in 1990, a year after the collapse of communism. Germany considers the reparations issue to be closed.

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