Poland’s governing Law and Justice party (PiS) has claimed victory in Sunday’s general election.
An exit poll gave the conservative nationalist party 43.6% of the vote, enough to take a majority in the lower house of parliament.
Its main rival, the centrist Civic Coalition (KO), had 27.4%.
PiS has been at loggerheads with the EU over reforms to Poland’s judiciary and has also been criticised over its position on gay rights.
“We have victory,” jubilant PiS leader Jaroslaw Kaczynski told supporters at party headquarters in Warsaw.
“We have four years of hard work ahead. Poland must change more and it must change for the better.”
If the exit poll proves accurate, calculations by private broadcaster TVN suggest PiS could have 239 MPs in the 460-seat lower house.
By the same calculations, KO would take 130 seats and the left-wing coalition Lewica, in third place, 43 seats. Turnout was more than 60%, the exit poll suggested.
Lewica was also celebrating its predicted result after left-wing parties lost their seats four years ago due to fragmentation. Robert Biedroń, one of the bloc’s three co-leaders and Poland’s first openly gay lawmaker, told a rally: “We are returning to parliament. We are going back to where the Polish left has always belonged.”
The first official results are expected later on Monday.
LGBT rights became the single biggest cultural issue ahead of the election. PiS – and the Roman Catholic Church – maintain that gay rights are a threat to traditional Polish families and values.
A year ago the EU ordered Poland to halt the application of a new law which critics said would have given PiS political control of the Supreme Court.
The governing party had argued that reforms were needed to remove judges appointed during the communist era and to make the court more efficient.
But the European Commission – the EU’s executive arm – argued that the reforms undermined the rule of law by giving the governing party control of the judiciary.