WARSAW — Mysterious tapes of high-level officials discussing what seem to be unsavory deals, recorded in the back room of a restaurant popular with the political elite, are threatening the careers of some of Poland’s most prominent leaders and perhaps even the survival of the current government.

Prime Minister Donald Tusk on Monday afternoon described the electronic eavesdropping, which occurred over many months and may have involved several locations, as “an attempt at a coup d’état, bringing down the Polish government by illegal means,” and called it well organized and unprecedented in Poland’s post-Communist history.

Although Mr. Tusk and other officials in the governing party criticized some of the behavior and language contained on the tapes, they focused the bulk of their wrath Monday on the eavesdropping itself.

Transcripts of several recordings, which were made at a restaurant favored by those eager to meet out of the public eye, were published over the weekend by Wprost, a weekly Warsaw newspaper. The paper said it did not know who had made the recordings and did not describe how it had obtained them.