BRUSSELS -- Far-right and Euroskeptic parties made sweeping gains in European Parliament elections Sunday -- triggering what one prime minister called a political "earthquake" by those who want to slash the powers of the European Union or abolish it altogether.
Voters in 21 of the EU's 28 nations went to the polls Sunday, choosing lawmakers for the bloc's 751-seat legislature. The other seven countries in the bloc already had voted in a sprawling exercise of democracy that began Thursday in Britain and the Netherlands.
One of the most significant winners was France's far-right National Front party, which was the outright winner in France with 26 percent support-- or 4.1 million votes.
"The sovereign people have spoken ... acclaiming they want to take back the reins of their destiny," party leader Marine Le Pen said in a statement.
She called the results "the first step in a long march to liberty."
French Prime Minister Manuel Valls, in an impassioned televised speech, called the National Front win "more than a news alert ... it is a shock, an earthquake."
French President Francois Hollande's office announced he would hold urgent talks first thing today with top government ministers in what French media called a crisis meeting.
All of Europe will have to deal with the fallout, analysts and politicians said.
Pro-European parties "have to take very seriously what is behind the vote," said Martin Schulz of the Socialist group in parliament.
Guy Verhofstadt, leader of the Liberal caucus in the European Parliament, conceded as much but said even after the vote, two-thirds of the European lawmakers would be "people who are in favor of the European Union."
Despite the Euroskeptic gains, established pro-EU parties were forecast to remain the biggest groups in the parliament. The conservative caucus, known as EPP, was forecast to win 211 seats, down from 274, but enough to remain the parliament's biggest group.
The National Front was not the only party benefiting from widespread disillusionment with the EU. Nigel Farage, leader of the fiercely Euroskeptical UKIP party, believed he was on track for a historic victory.
"It does look to me [as if] UKIP is going to win this election and yes, that will be an earthquake, because never before in the history of British politics has a party that is seen to be an insurgent party ever topped the polls in a national election," he said.
"I don't just want Britain to leave the European Union," he added. "I want Europe to leave the European Union."
The first official results announced late Sunday had UKIP at about 30 percent, some 12 percent higher than the last European elections in 2009.
In Denmark, with 95 percent of votes counted, the main government party, the Social Democrats, retained their five seats to remain the biggest party.
But the big winner in the elections was the populist, opposition Danish People's Party, which won three more seats for a total of four. A 1-year-old party in Germany that wants that country to stop using the euro single currency reportedly won 6.7 percent of the vote.
In Greece, with a quarter of the votes counted, the leftist Euroskeptic Syriza party led with 26.49 percent. The extreme right Golden Dawn party was third with 9.33 percent.
Doru Frantescu, policy director of VoteWatch Europe, an independent Brussels-based organization, said Europe's mainstream political parties won enough seats to still muster a majority on issues where they concur.
"The problem comes when the left, the Socialists and EPP will not agree on issues," Mr. Frantescu said.
In the incoming European Parliament, he said, fringe parties will be able to exert more pressure on key topics, ranging from how liberal to make the internal European market for services or the proper mix of energy sources to which clauses should be scrapped in a proposed trade and investment agreement with the U.S.
In the Netherlands, however, the right-wing Euroskeptic Party for Freedom surprisingly dropped a seat from five to four. Its outspoken leader, Geert Wilders, said in a statement his party looked forward to working with Ms. Le Pen in Europe, calling the National Front leader "the next French president."
The European Parliament estimated turnout was narrowly up from the last election in 2009, at 43.1 percent, reversing years of declining turnouts.
Voters also put new parties in the European Parliament, with preliminary results showing that Sweden elected the first lawmaker from a feminist party and the Dutch returned one representative for the Party for the Animals.