Donald Tusk, leader of the largest opposition grouping Civic Coalition (KO), speaks after the exit poll results are announced in Warsaw, Poland, 15 October 2023; Credit: Reuters/Kacper Pempel

WARSAW (Reuters) - Poland's ruling nationalists appeared on Monday 16 October 2023 to have lost their parliamentary majority in the nation's most pivotal election in decades, potentially opening the way for opposition parties to seize power in what would be a huge political shift.

Poland has repeatedly clashed with the European Union over the rule of law, media freedom, migration and LGBT rights since Law and Justice (PiS) came to power in 2015, but opposition parties have vowed to mend ties with Brussels and undo reforms critics say undermine democratic standards.

An Ipsos late exit poll on Monday gave PiS 36.6% of the vote, which would translate into 198 lawmakers in the 460-seat lower house of parliament.

Opposition parties, led by the former European Council president Donald Tusk's liberal grouping Civic Coalition (KO), were projected to together win 248 seats, with the KO seen winning 31.0% of ballots cast.

Victory for the opposition in a vote seen by analysts as the most significant election for Europe in years, could potentially redefine the relationship between Brussels and the largest member state in central and eastern Europe. 

KO lawmaker Cezary Tomczyk called on President Andrzej Duda with the task of forming a government with Tusk at the helm.

"We demand from the president that the democratic camp be able to choose a candidate for prime minister," he told private broadcaster TVN 24. "The natural candidate for prime minister is Donald Tusk."

However, if official results confirm the exit poll, Tusk and his allies from the centre-right Third Way and the New Left may have to wait weeks or even months before getting a turn at forming a government.

Duda, a PiS ally, has said he would give the first shot to the winning party, suggesting Prime Minister Mateusz Morawiecki or another party leader would have the chance first. But with the far-right Confederation scoring 6.4%, below expectations, he will have few obvious allies, experts said.

The late exit poll had been delayed, with some commentators saying that it was due to the unexpected record turnout.

Television footage showed several hundred people, mostly young, waiting in a long line at one polling station in the western city of Wrocław to vote. Local residents were bringing them hot tea and blankets as well as some food.

Some of those in line said they waited for six hours. The polling station closed just before 03:00 (01:00 GMT), some six hours after the voting stations were set to officially to close.

Tusk, 66, was jubilant following the announcement of the first exit poll results on Sunday 15 October 2023. "Democracy has won [...]. This is the end of the PiS government," he told party members.

PiS leader Jaroslaw Kaczynski, 74, told officials gathered at the party's headquarters in central Warsaw that it was not clear whether Sunday's showing would translate into a new term in office. "We have to have hope that regardless of whether we are in power or in opposition, our project will continue [...]. We will not let Poland lose [...] the right to decide its own fate."

Poland's zloty currency firmed following the result, and was about 1.2% stronger at 06:03 GMT.