Eurosceptic nationalists scored stunning victories in European Parliament elections in France and Britain on Sunday as critics of the European Union more than doubled their seats in a continent-wide protest vote against austerity and unemployment.
French Prime Minister Manuel Valls called the breakthrough by Marine Le Pen's anti-immigration, anti-euro National Front in one of the EU's founding nations a political "earthquake".
Anti-establishment parties of the far right and hard left, their scores amplified by a low turnout, made gains in many countries although in Germany, the EU's biggest member state with the largest number of seats, and Italy, the pro-European centre ground held firm.
In a vote that raised more doubts about Britain's long-term future in the EU, Nigel Farage's UK Independence Party, which advocates immediate withdrawal, led the opposition Labour party and Prime Minister David Cameron's Conservatives comfortably with almost half the results declared.
A jubilant Le Pen, whose party beat President Francois Hollande's ruling Socialists into third place, told supporters: "The people have spoken loud and clear ... they no longer want to be led by those outside our borders, by EU commissioners and technocrats who are unelected.
"They want to be protected from globalisation and take back the reins of their destiny."
With 80 percent of votes counted, the National Front had won 26 percent of the vote, comfortably ahead of the conservative opposition UMP on 20.6 percent, with the Socialists on 13.8, their second heavy defeat in two months after losing dozens of town halls in March.
First official results from around the 28-nation bloc showed the pro-European centre-left and centre-right parties will keep control of around 70 percent of the 751-seat EU legislature, but the number of Eurosceptic members will more than double.
The centre-right European People's Party, led by former Luxembourg Prime Minister Jean-Claude Juncker, was set to win 212 seats, preliminary results issued by the parliament showed.
"As the EPP has a strong lead ... I am ready to accept the mandate of the European Commission president," Juncker told reporters in parliament. "We will have a clear pro-European majority in this house."
The centre-left Socialists, led by outgoing European Parliament President Martin Schulz of Germany, were in second place with 186 seats followed by the centrist liberals on 70 and the Greens on 55. Eurosceptic groups were expected to win about 141 seats, according to a Reuters estimate, the far left 43 and conservatives 44.
A glum looking Schulz would not concede defeat, telling reporters he would negotiate with other parties.
"It is a bad day for the European Union when a party with such a racist, xenophobic and anti-Semite programme gets 24-25 percent of the vote in France," he said. "But these voters aren't extremists, they have lost trust, they have lost hope."
Ukip Make Big Gains
The political fallout may be felt more strongly in national politics than at EU level, pulling mainstream conservative parties further to the right and raising pressure to crack down on immigration.
In Britain, where voting took place last Thursday, UKIP won 27.5 percent of the vote, with the Labour opposition on 25.4 percent and the Conservatives on 24 percent, although results from Scotland were still to be factored in.
That will pile pressure on Cameron, who has promised Britons an in/out referendum on EU membership in 2017 if he is re-elected next year, to take an even tougher line in Europe. His pro-European Liberal Democrat coalition partners were set to hold just one seat, a loss of nine seats.
"The whole European project has been a lie," Farage said on a television link-up with Brussels. "I don't just want Britain to leave the European Union, I want Europe to leave the European Union."
In Italy, pro-European Prime Minister Matteo Renzi's centre-left Democratic Party was on course for a resounding win, building a huge lead over the anti-establishment 5-Star Movement of former comic Beppe Grillo, near complete results showed.
The anti-immigration far right People's Party topped the poll in Denmark and the extreme-right Jobbik, widely accused of racism and anti-Semitism, finished second in Hungary.
In the Netherlands, the anti-Islam, Eurosceptic Dutch Freedom Party of Geert Wilders - which plans an alliance with Le Pen - underperformed but still finished joint second in terms of seats behind a pro-European centrist opposition party.
Although 388 million Europeans were eligible to vote, fewer than half cast ballots. The turnout was officially 43.1 percent, barely higher than the 2009 nadir of 43 percent, despite efforts to personalise the election with the main political families putting forward a leading candidate, or "Spitzenkandidat".
In Germany, Chancellor Angela Merkel's Christian Democrats secured 35.3 percent of the vote, down from a 23-year-high of 41.5 percent in last year's federal election but still a clear victory. The centre-left Social Democrats, her coalition partners, took 27.3 percent.
The anti-euro Alternative for Germany won seats for the first time with 7 percent, the best result so far for a conservative party created only last year to oppose bailouts and call for weaker states to be ejected from the single currency.
Greek Far Left Gains
In Greece, epicentre of the euro zone's debt crisis, the radical left anti-austerity Syriza movement of Alexis Tsipras won the vote but failed to deliver a knockout blow to the government of Prime Minister Antonis Samaras.
An official projection gave Syriza 26.7 percent, ahead of Samaras's conservative New Democracy on 22.8 percent, reflecting popular anger at harsh spending cuts adopted in recent years to meet the terms of Athens's EU/IMF bailout programme.
"Europeans are celebrating the defeat of the bailout and austerity in the country the European leadership turned into the guinea pig of the crisis," Tsipras said.
The two parties in the coalition, New Democracy and PASOK, won a combined vote larger than that of Syriza, and political analyst Theodore Couloumbis said the government's survival was not at stake despite its narrow two-seat majority.
Sunday was the fourth and final day of voting in elections to the European Parliament, which is an equal co-legislator with member states on most EU laws.
Far-right and radical left groups will have roughly a quarter of the seats, enough to gain a much louder voice but probably not to block EU legislation.
Officials said final results and seat allotments would probably be finalised later on Monday.
The record low turnout was in Slovakia, with just 13 percent. The highest was 90 percent in Belgium, where voting is compulsory and there was a general election the same day.
Sweden appeared to have elected the only feminist party member of the EU assembly.