TALLINN (Reuters) - European Union states will this month debate increasing pressure on Poland to uphold the rule of law, sources said, as the next stage in a process that could see its government formally denounced as anti-democratic.

A man hold flags in front of the Supreme Court during a protest against the Supreme Court legislation in Warsaw, Poland, July 22, 2017. REUTERS/Kacper Pempel

The nationalist Law and Justice (PiS) government in Warsaw has pushed through reforms to the judiciary and media that critics within the EU say have weakened the democratic order.

PiS rejects the criticism, accuses Brussels of overstepping its mandate and says it has broad backing for its reforms within Poland, a country of 38 million and formerly communist eastern Europe’s dominant economy.

After more than a year of growing pressure from the European Commission, the executive on Wednesday asked the bloc’s 28 EU affairs ministers to discuss its concerns on Sept. 25, the day after national elections in Germany.

The Commission’s deputy head Frans Timmermans will brief the ministers on his so far futile efforts to persuade Warsaw to shift its position, the sources said.

German Chancellor Angela Merkel has joined the growing chorus of those calling for firmer action on Poland and discussed the matter with the Commission’s chief, Jean-Claude Juncker.

Should Warsaw remain adamant, it eventually risks losing generous EU handouts if it continues to upset its wealthier peers that chip in for the funds, a debate gradually heating up in the bloc.

For now, the EU has limited firepower at its disposal.

But it could trigger Article 7 proceedings under which it would ask the other 27 EU states to formally state that the rule of law was under threat in Poland - an action unprecedented in EU history.

Timmermans has set a clear red line by saying that Article 7 would be opened should Warsaw start to fire the country’s Supreme Court judges under the judicial overhaul.

The dispute highlights Warsaw’s growing isolation in the EU since the eurosceptic PiS won power there in 2015, but also a growing east-west divide within the bloc.

Launching Article 7 would be a major embarrassment for Poland, but its regional ally Hungary - whose leader Viktor Orban also has a track record of crossing swords with Brussels - has made clear it would block any sanctions against it under the punitive procedure.

In the west, increasingly frustrated with multiplying feuds with Warsaw that also touch on migration and environmental issues, some express renewed doubts about the 2004 EU enlargement that added eight ex-communist countries to the bloc.

In Poland, opposition parties sound alarm that PiS is reneging on fundamental EU values and could eventually risk sabotaging Poland’s EU membership, which gave the country billions of euros and anchored it in the western world after decades of the Moscow-imposed communism after World War Two.

But PiS has largely been successful in rallying its supporters around what it presents as standing up for Poland’s national interests against the EU dictate, just as Orban has portrayed his own feuds with the bloc to his voters.

The more immediate effect is that Warsaw is hemorrhaging political influence in the EU and has less capacity to shape the bloc’s policies despite being the sixth largest state by population, and the fifth one after Britain leaves.