Romania's ruling coalition filed a legal complaint on Thursday accusing 15 opposition leaders of defaming the ex-communist state that has been mired in political turmoil.
The move is another twist in a saga gripping Romania that has seen Prime Minister Victor Ponta and his coalition suspend President Traian Basescu and try to trim the powers of the constitutional court.
The complaint, filed with the public prosecutor's office, came a day after Brussels released a mixed report on Romania's efforts to reform its judiciary and fight corruption since joining the European Union in 2007.
While the European Commission praised Romania for some reforms, it said recent developments "raise serious doubts" about its understanding of the rule of law. And commission president Manuel Barroso said: "Recent events in Romania have shaken our trust."
Even though the ruling coalition instigated many of the developments of concern to the EU, the Social-Liberal Union (USL) coalition said in its complaint that it was the centre-right opposition that was "undermining the national economy" and "spreading false information".
They "grossly manipulated public opinion and European and international bodies," USL official Eugen Nicolaescu said, adding that the economy was being "seriously affected by this dangerous disinformation campaign".
Ponta had urged his cabinet hours earlier to reject the opposition's "lies and fascist propaganda", and the ruling alliance also accused the opposition of having presented "totally constitutional steps as a coup d'etat".
Ponta and Basescu have been locked in a bitter squabble since Ponta's coalition took office in May after the former centre-right government fell following a no-confidence vote.
USL lawmakers this month suspended Basescu, who was once one of Romania's most popular politicians but whose ratings plummeted amid austerity cuts in 2010. Romanians are supposed to vote on his impeachment July 29.
The European Commission also voiced concern over Ponta's use of decrees to strip powers from the constitutional court.
Other contentious moves have included removing the opposition speakers of both houses of parliament and quashing the role of ombudsman, who had the power to contest government decrees and emergency orders.
Ponta has also been embroiled in a personal scandal after British journal Nature said he plagiarised large chunks of his PhD thesis in 2003.
But on Thursday, a commission set up by Romania's education ministry cleared Ponta, saying his thesis "respects the academic demands of the time".
The Strasbourg-based Council of Europe's Parliamentary Assembly meanwhile called on Romanian politicians on Thursday to "respect democratic standards and the principles of the rule of law".