Outgoing EU Council President Donald Tusk on Monday accused the governing conservatives from his home country of Poland of exploiting state institutions for political purposes and propaganda.
The former Polish prime minister, who some believe is eyeing a political comeback at home once his EU term ends in November, was testifying before a parliamentary committee investigating value-added tax (VAT) fraud.
The Law and Justice (PiS) party in power since 2015 has accused the previous centrist governments of Tusk and another former premier Ewa Kopacz of not having devoted enough resources to the fight against the fraud.
They claim that this has led to state budget shortfall of up to an estimated 250 billion zloty (59 billion euros, $66 billion).
Tusk called the accusations "odious and absurd", arguing it was "all propaganda" in the run-up to the October general election and that prosecutors "never showed an interest" in the case.
Speaking to reporters, he called the committee's work "political abuse of power". Most of its members belong to the PiS.
He has already been questioned as a witness in investigations into the 2010 presidential jet crash in Smolensk, Russia which killed then Polish head of state Lech Kaczynski and 95 others.
PiS leader Jaroslaw Kaczynski, the late president's twin brother, has blamed Tusk's circle of "moral responsibility" for the crash.