European Council President Donald Tusk told the government in his home country Poland to respect the constitution and not to add fuel to the fire of “political civil war” in a speech in Warsaw on May 3, Poland’s Constitution Day.

As a high-ranking EU official, Tusk could not be more direct in criticism of the incumbent government led by the populist and eurosceptic right-wing party Law and Justice (PiS). PiS is at loggerheads with Brussels over a number of issues, including the reform of the judiciary that the EU says breaches the rule of law by putting courts under political control of the ruling party.

“It can’t be that those in power once a year celebrate constitution day, but disrespect it on a daily basis,” Tusk said in his speech at the University of Warsaw.

He also warned against toxic political divisions in Poland that provide ground for rhetoric of excluding opponents, especially after winning elections.

“Politics aren’t a cup game. You can claim a cup after a winning match but whoever wins an election, they can’t say Poland is theirs,” Tusk, a well-known football fan, also said.

Tusk’s speech came amidst ever-intensifying speculation about his return to domestic politics to lead the opposition’s charge against PiS. 

Tusk’s second term as the head of the European Council ends in December, after elections to the European Parliament taking place on May 26 and also after the Polish general election due in October or November (the exact date has not been set yet).

It has been speculated, however, that Tusk could shorten his term in Brussels to try and use his influence to remove PiS from power. He might do it in June, after the elections to the European Parliament when the EU will also enter a new cycle of picking its top officials.

June 4, the 30th anniversary of Poland’s first partly free election that marked the end of the communist era in the country and the entire CEE region, appears to be the perfect date for Tusk to kick-start his return.

For now, opposition to PiS remains on the defensive, trailing in the polls and struggling to find a narrative that would convince voters to turn against the ruling party.