Commission officials have given Warsaw three months to rethink the changes which critics warn undermine democracy and fly in the face of EU law.
But Bulgaria has just taken over the EU presidency and is hoping for compromise which will avoid the need for heavy sanctions which could see Poland suspended from the bloc.
New Polish Prime Minister Mateusz Morawiecki has met with European Commission President Jean-Claude Juncker to try to resolve the issue and EU member states will hold their first talks with Poland on February 27.
Bulgarian Foreign Minister Ekaterina Zaharieva said Sofia was hoping for a compromise amid increasing tensions.
She said: “Poland should be listened to.
“We hope during this period that in the negotiations with the Commission Poland will do some reform of their reform and agree with the Commission and the situation will calm down.”
Bulgarian Prime Minister Boyko Borissov said the EU should avoid pushing matters to the point where the other 27 member states had to vote on whether to sanction Warsaw – a decision he said would give governments “sleepless nights”.
But EU officials have dismissed suggestions Bulgaria wants to put a brake on moves to penalise its fellow ex-communist member state.
An official said: ”The Commission is working to make it work within three months.
“There are things in the works. Next month’s ministerial meeting will be a chance to hear Poland’s case.
“In an ideal world, we will sort this out and there will be no vote. There is ample time to make it work.”
Two years of bitter feud between the eurosceptic, nationalist government in Warsaw and the EU have isolated Poland – once praised as the posterchild of post-communist transition – and weakened EU unity as it enters key negotiations over its next long-term budget and grapples with Brexit.