BRUSSELS — As voters in all 28 European Union countries elect a new shared parliament, here are some key races to watch in the battle to fill the 751 seats in the European Parliament:
Italy's anti-migrant, anti-Islam interior minister, Matteo Salvini, has been campaigning hard to boost his right-wing League party to become the No. 1 party in Italy and possibly Europe.
Salvini has been using his hard-line credentials to expand a parliamentary group of European populists that already includes far-right politicians in France, Germany and Austria. Salvini is promising to restore sovereignty over key issues like immigration to national capitals, thwarting the EU's drive toward closer integration of its members.
In Europe, the populists will find it difficult to deliver on their transformation promises. But Salvini is also looking to capitalize on the outcome of the European elections to boost his power at home in the League's uneasy populist ruling coalition with the left-wing 5-Star Movement.
Salvini could use European electoral gains to leverage his position in the government and pass policies important to his base of northern Italian entrepreneurs, like a flat tax or the high-speed train connecting Lyon, France, with Turin.
Most analysts believe that Salvini is unlikely to seek an early election in Italy even with a big victory on the European stage. The 5-Star Movement, on the other hand, could decide to pull the plug on the coalition government.
France is looking at an epic battle between pro-EU centrist President Emmanuel Macronand anti-immigration, far-right flagbearer Marine Le Pen in the European Parliament vote, a duel over Europe's basic values.
A loss for Macron's Republic on the Move party would cripple the French leader's grand ambitions for a more united Europe. Macron wants EU countries to share budgets and soldiers and work even more closely together to keep Europe globally relevant and prevent conflict.
For Macron, Le Pen represents the "leprosy" of nationalism that is eating the EU from within. For Le Pen, the race is a battle to preserve European civilization from the threat of "massive immigration" and uncontrolled globalization.
Le Pen's party, then called the National Front, won France's European parliamentary elections in 2014, but today she is looking beyond home territory. She has traveled to numerous European capitals recently to lend support to populist candidates, with the goal of enlarging their parliamentary group.
France has 34 lists of candidates in the European election, but Macron crushed France's traditional right and left parties in 2017 when he won the presidency, and they're still struggling.
Germany's governing parties look likely to lose some ground in the European Union's most populous country, while the environmentalist Greens and the far-right Alternative for Germany parties are eyeing gains.
The vote is shaping up to be a particularly tough test for the center-left Social Democrats, the junior partners in Chancellor Angela Merkel's governing coalition. They have been struggling badly in polls and there is widespread speculation that a poor performance could hasten the end of Merkel's coalition government.
For Merkel's conservative Christian Democratic Union, it is the first test for new leader Annegret Kramp-Karrenbauer since Germany's longtime chancellor gave up her party's leadership last year.
The Greens have been soaring in polls, partly at the Social Democrats' expense, and hope to convert that support into votes. And Alternative for Germany hopes to strengthen its presence in the European Parliament, adding to its strong contingent in Germany's national legislature.
Many of Germany's 96 seats in the European Parliament are also likely to go to a variety of fringe parties.
Hungarian Prime Minister Viktor Orban describes the European Parliament vote as "decisive" for Hungary and Europe, an opportunity for populist and anti-migration forces to have a larger say in setting the agenda in Brussels.
While his party's victory in Hungary is unquestioned, where the allegiances of Orban and his right-wing Fidesz party will lie after the election on the European scene is far less certain.
Fidesz's membership in the center-right European People's Party, currently the largest group in the EU legislature, was suspended in March because of concerns about the state of Hungary's democracy. So Orban has spent the past few weeks hosting far-right, nationalist and populist politicians at his new office in Buda Castle.
Orban says he wants to stay in the center-right bloc while getting the EPP to cooperate more closely with nationalist and populist parties like Salvini's League. That notion has been emphatically rejected by leading politicians from the EPP, including German Chancellor Angela Merkel.
If Salvini's populists do well on Sunday, Orban could leave the EPP and try to get some of the party's more right-wing members to join Salvini in a new, more radical alliance.
While Hungary has largely stemmed migration, Orban's opposition to migrants still bears fruit, and pollsters expect Fidesz to win as many as 14 of Hungary's 21 seats in the EU parliament.
Britain wasn't supposed to take part in the European Parliament elections at all, but had to organize a last-minute campaign when its planned March exit from the EU was postponed.
The British voting Thursday came amid intense political turmoil sparked by its 2016 referendum to quit the EU. Embattled Prime Minister Theresa May will now step down as Conservative Party leader on June 7 after failing to deliver Brexit.
Both Britain's Conservatives and the Labour Party are predicted to be heading for an electoral pasting in the European vote due to the chaos over Brexit.
Britain's Brexit party, led by Nigel Farage, has appeared to gain strength in recent voter surveys. Farage says he hopes to have the shortest possible tenure as a European Parliament lawmaker because he wants Britain to leave the EU as quickly as possible.
The U.K. has 73 seats at the European Parliament, and its lawmakers would lose their jobs when their country leaves the EU.
Sunday's European Parliament vote in Austria has been upended by the sudden collapse of Austria's governing coalition in a scandal that has tarnished the far-right Freedom Party. It will serve as a first test of support ahead of an early national election expected in September.
Heinz-Christian Strache quit last weekend as vice chancellor and Freedom Party leader after a leaked video showed him appearing to offer favors to a purported Russian investor during a boozy meeting on the Spanish island of Ibiza two years ago. Chancellor Sebastian Kurz then called for a new election and is now running an interim government with experts replacing the Freedom Party's ministers.
The European Parliament election should offer clues as to whether the popular Kurz's conservative People's Party will benefit from the scandal. But regardless of the result, Kurz is expected to face a small opposition party's no-confidence motion in parliament on Monday, and it's unclear whether he will keep his job.
Colleen Barry in Milan, Italy, Geir Moulson in Berlin, Pablo Gorondi in Budapest, and Elaine Ganley and Angela Charlton in Paris contributed to this report.