Jarosław Kaczyński, head of Poland’s opposition Law and Justice (PiS), has urged PiS lawmakers and members to block Ukraine from joining the European Union unless Ukraine changes its current course. In a letter to party members, Kaczyński said PiS would not allow Ukraine’s EU accession if it wins the next elections.

Kaczyński argued that Ukraine cannot be admitted to the EU unless it fully abandons what he described as the country’s approach to the “cult of Bandera” and the glorification of the Ukrainian Insurgent Army (UPA) and the Organisation of Ukrainian Nationalists (OUN). He also appealed to the idea that Poland and other European countries cannot tolerate “genocidal acts” against their own nations.

He further claimed Poland and Polish citizens have borne “enormous financial costs” for maintaining Ukraine’s state and its army, adding that without broad external support—particularly from Poland—Ukraine’s taxpayers cannot sustain the country’s capacity to function and fight. The letter also referenced a controversy involving the naming of a Ukrainian unit after people Kaczyński described as responsible for violence against Poles during the Volhynia and Eastern Galicia events