Donald Tusk, the leader of Poland’s largest liberal opposition grouping Civic Coalition (KO) and a potential candidate to become prime minister, will likely travel to Brussels next week, a senior lawmaker from his party said on Thursday, as he tries to unblock funds frozen over rule-of-law concerns. Pro-European Union (EU) opposition parties won a majority in Sunday’s election, a huge shift for Poland after eight years of feuding with Brussels over issues ranging from judicial independence to LGBT rights. It also represents a setback for right-wing populism in the EU. The new government has not yet formed but Tusk is a strong potential candidate to lead it, with the ruling nationalist Law and Justice (PiS) party unlikely to find a coalition partner.