Voters in Ireland and the Czech Republic go to the polls Friday on the second day of marathon EU elections, after the Netherlands kicked off the ballot with a strong showing by the far right.
The Freedom Party (PVV) of anti-immigration Dutch eurosceptic Geert Wilders was set for a major boost in the incoming European Parliament, after an exit poll put it in second place with seven seats.
That was expected to be just the first in a string of gains for far-right parties across the EU that surveys suggest will see them claim a quarter of the 720 seats up for grabs.
Most of the European Union's 27 nations -- including powerhouses Germany and France -- hold balloting on Sunday, with 370 million people eligible to vote overall.
The vote comes at a time of major geopolitical instability almost two and a half years into Russia's war on Ukraine, with warnings the Kremlin was targeting the elections with a disinformation campaign.
The far right is looking to tap into grievances among voters fatigued by a succession of crises over the past five years from the Covid pandemic to the fallout of Moscow's invasion.
The prospect of a lurch to the right has rattled the European Parliament's main groupings, the conservative European People's Party (EPP) and the leftist Socialists and Democrats.
They remain on course to be the two biggest blocs but current European Commission chief Ursula von der Leyen, who comes from the EPP, may need to glean support from part of the far right to secure a second term.
With an eye on the horse-trading that may be needed, the polyglot former German defence minister has been courting Italian premier Giorgia Meloni, who heads the post-fascist Brothers of Italy party.
French President Emmanuel Macron warned Thursday the EU risked being "blocked" by a big far-right presence in the European Parliament.
In the Netherlands, Wilders trumpeted his party as the "biggest winner" as he continued to ride a wave of anti-immigration sentiment after victory at national polls last year.
But his chief opponent Frans Timmermans, whose Green-left alliance appeared set for first place with eight seats, insisted strong showings by pro-European parties sent an "important signal".
Ireland takes up the baton on Friday and for the first time in a European election migration and the asylum system have emerged as leading issues there too.
Many candidates are running on an anti-immigration platform, either as independents or as members of various fringe nationalist parties, which until now have enjoyed limited success at the ballot box.
With around 20 percent of the population born outside the country and record levels of asylum seekers arriving in Ireland this year, anti-migrant sentiment has escalated.
The main question though remains whether centre-right Fine Gael of prime minister Simon Harris will win a bigger vote share than the main opposition party Sinn Fein, with local elections also held the same day.
Support for the leftist-nationalist Sinn Fein has declined sharply in the last year, with its progressive and pro-migration stances appearing at odds with many of its core working-class voters.
To the east, Czech politicians face widespread apathy to the EU vote, after the country had the second lowest turnout last time around in 2019 at 28.72 percent.
Polls put the centrist ANO movement of billionaire former prime minister Andrej Babis in the lead, ahead of a centre-right coalition.
Fears of Russian meddling were raised in the run-up to the vote after Czech authorities busted a website alleged to be a Kremlin front used to push Russian propaganda.
The probe into the Voice of Europe website has since spread to Belgium -- home of the European Parliament -- after allegations that EU lawmakers were paid by the outlet.
Over the weekend, scrutiny will shift to the EU's bigger economies as they open polling stations.
Marine Le Pen's National Rally is predicted to come out on top in France, as is Meloni's party in Italy and Hungarian Prime Minister Viktor Orban's far-right Fidesz.
In Germany, the extreme-right AfD is polling second, behind the opposition conservatives. In Austria, the far-right Freedom Party looks on track for victory.