Prosecutors in Warsaw have launched an investigation into former premier Donald Tusk’s alleged role in the crackdown on a controversial importer of Russian coal in 2014.

The investigation is seen as an attempt to weaken Tusk, whose party, Civic Platform (PO), is the main rival of the ruling Law and Justice (PiS) in the general election due later this year, probably in October.

The investigation will probe whether Tusk abused his position while in the prime minister’s seat by “ordering without legal and factual basis an inspection of Sklady Wegla [the importer in question] to force the cessation of coal imports from the Russian Federation”, the prosecutors said in a statement dated April 11 but made public by the government-controlled broadcaster TVP on April 25.

The prosecutors said that the inspection was beneficial to competing coal traders and was detrimental to the subject company’s interests. In theory, Tusk could face charges with a potential jail time of up to 10 years.

The investigation has major political undertones. The coal importer’s owner, Marek Falenta, orchestrated covert recording of politicians at a Warsaw restaurant in 2015, a scandal that helped PiS win that year’s election at the expense of PO, many of its leading figures having featured on Falenta’s tapes.

The investigation into Tusk’s alleged crackdown on Falenta’s company follows the businessman’s request to launch the probe, accompanied by a defamation claim against Tusk.

Tusk hinted in the past that Falenta’s secret taping of politicians might have borne markings of Russia’s involvement in the toppling his then government, paving PiS' way to power.

PiS, which has turned vehemently anti-Russian in the wake of the Kremlin’s war against Ukraine, denies having anything to do with the scandal. But the ruling party appears poised to zero in on Tusk, Poland’s only opposition politician with enough clout to pose a real threat to its rule.

The ruling party is beleaguered by crises, including stubborn double-digit inflation and, most recently, failure to ensure the transit of millions of tonnes of Ukrainian grain through Poland, damaging the country's farmers.  

The politically-controlled prosecution – headed by the key government figure Zbigniew Ziobro, who is both justice minister and prosecutor-general – is widely expected to push on with Tusk’s case, even if only to keep him in the headlines across the government-controlled media until the election, observers say.

“They may try to make me a fugitive,” Tusk said, referring to a 1990s film, according to a report by the opposition-leaning newspaper Gazeta Wyborcza. “But this movie ends well. Those going after me will be held accountable.”