BRUSSELS - Pivotal elections for the European Union parliament reach their climax Sunday as the last 21 nations go to the polls and results are announced in a vote that boils down to a continentwide battle between euroskeptic populists and proponents of closer EU unity.
Right-wing nationalists who want to slash immigration into Europe and return power to national governments are expected to make gains, though mainstream parties are expected to hold onto power in the 751-seat legislature that sits in both Brussels and Strasbourg.
Salvini vs Macron
Leading the challenge to the established order is Italy's hard-line interior minister, Matteo Salvini, head of the League party, who is assembling a group of like-minded parties from across Europe.
"We need to do everything that is right to free this country, this continent, from the illegal occupation organized by Brussels," Salvini told a rally in Milan last weekend that was attended by the leaders of 11 nationalist parties.
Proponents of stronger EU integration, led by French President Emmanuel Macron, argue that issues like climate change and reining in immigration are simply too big for any one country to tackle alone.
Macron, whose country has been rocked in recent months by the populist yellow vest movement, has called the elections "the most important since 1979 because the (European) Union is facing an existential risk" from nationalists seeking to divide the bloc.
Sunday promises to be a long day and night for election watchers - the last polls close at 11 p.m. (2100 GMT) in Italy, but the European Parliament plans to begin issuing estimates and projections hours earlier with the first official projection of the makeup of the new parliament at 11:15 p.m. (2115 GMT).
Right-wing populists top opinion polls in two of the big four member states - Italy and supposedly exiting Britain - and could also win in a third, France, rattling a pro-Union campaign championed by centrist Macron.
However, exit polls in some countries that have already voted have given pro-EU parties some comfort. The Dutch Labour party, all but written off, looks to have finished first, helped by the visibility of having the EU socialists' lead candidate, current EU deputy chief executive Frans Timmermans.
In the Netherlands pro-Union parties scored 70%, up three points on the last European Parliament vote in 2014, and left the upstart anti-immigration party of Thierry Baudet fourth at 11%.
The Dutch also turned out in bigger numbers, albeit at just 41%, reinforcing hopes in Brussels of reversing a 40-year trend of declining turnout that critics cite as a "democratic deficit" that undermines the legitimacy of European Union lawmaking.
An exit poll after Friday's vote in deeply pro-EU Ireland pointed to an expected "Green Wave." Across the bloc, concerns about climate change and the environment may bolster the pro-EU Greens group and could mean tighter regulations for industry and for the terms the EU may set for partners seeking trade accords.
As the dust settles on four days of elections, European leaders will begin the task of selecting candidates for the top jobs in the EU's headquarters in Brussels. The leaders meet for a summit over dinner Tuesday night.
Current European lawmakers' terms end July 1 and the new parliament will take their seats in Strasbourg the following day.
Reuters contributed to this report.