A top EU official on Tuesday hailed progress in talks with Poland over controversial reforms Brussels fears undermine judicial independence, but warned Warsaw it must produce "concrete results" in the coming weeks.
European Commission Vice President Frans Timmermans said there was a "clear willingness" to solve the festering row between Poland and the EU.
Brussels launched unprecedented legal action against Warsaw in December over "systemic threats" to the independence of the Polish judiciary, and on Tuesday Timmermans presented his assessment of Warsaw's response to EU ministers in Luxembourg.
"We are making progress... there is a clear willingness on both sides to continue making progress," Timmermans said.
Earlier this month, following talks in Warsaw between Timmermans and the rightwing government, the Polish parliament made amendments to the controversial reforms.
On Tuesday, Timmermans said it was "positive that we're now making steps forward but we still need concrete results in the days and weeks to come", urging Poland to come up with answers by May 14.
Poland's EU Affairs Minister Konrad Szymanski said Warsaw would not act "under international pressure" and warned that "all scenarios are still on the table".
The stakes are high if Warsaw fails to satisfy Brussels.
It could be stripped of its voting rights in the bloc under the Article 7 procedure of the EU treaty -- covering systemic threats to the rule of law -- which has never been used against a member state before.
However, Poland's ally Hungary, which has also clashed with Brussels over democracy issues, has vowed to veto any sanction.
The tussle with Warsaw is part of a pattern of rising tension within the EU between the liberal governments of the bloc's western members and some of its more conservative eastern countries.
French President Emmanuel Macron warned on Tuesday that divisions between democracy and authoritarianism in Europe were becoming like a "civil war", in a thinly-veiled reference to the likes of Poland and Hungary.