WARSAW (Reuters) -A Polish parliamentary commission will inform prosecutors that the former prime minister's role in an abortive plan to organise elections by postal vote during the COVID pandemic may constitute a crime, its deputy chairman said on Thursday.

Donald Tusk's pro-European coalition government, in office since December, has made a priority of holding to account those it accuses of wrongdoing under the previous nationalist Law and Justice (PiS) administration. Pressing criminal charges against such a high-ranking figure would mark a dramatic escalation of this process.

"This is a political action by the commission, which is trying to use the mechanism of an investigative commission to fight political competition," former Prime Minister Mateusz Morawiecki said in an emailed statement.

He has previously denied wrongdoing in the matter, saying that the decision to try to organise a postal vote for the 2020 presidential election was in the interests of public safety.

The parliamentary commission has questioned Morawiecki this week on the plan to hold a postal vote. Like many countries, Poland was under strict lockdown measures at the time the election was meant to be held, in May that year.

The plan was abandoned due to splits on the issue in the then ruling coalition and questions over its legality, but the printing of postal ballots that were never used cost the state at least 70 million zlotys ($17.77 million), according to the current government.

It says that those responsible for such a sum of public money going to waste may have committed crimes.

Jacek Karnowski, a lawmaker from the ruling coalition and the deputy chairman of the commission investigating the issue, told state news agency PAP that it would "definitely" inform prosecutors that a crime may have been committed in the case of Morawiecki.

The 2020 presidential election was postponed and finally held on June 28, with PiS-ally Andrzej Duda winning a second term in office in a run-off vote held on July 12.

($1 = 3.9395 zlotys)

(Reporting by Alan CharlishEditing by Frances Kerry)