The Czech Republic and Ireland voted Friday in European Parliament elections expected to boost eurosceptic parties despite a surprise setback for Dutch populists on the polls' first day.
With 26 million people out of work across the European Union, eurosceptic and far-right parties have picked up massive support on anti-immigration and anti-EU platforms.
The latest opinion polls suggest they could secure almost 100 seats in the new parliament, trebling their number in the 751-seat assembly, and may top the polls in Britain, France and Italy.
Friday results showed that the UK Independence Party (UKIP) led by Nigel Farage surged in local council elections, giving the anti-EU and anti-immigration group hope for a similar breakthrough in the European Parliament polls.
But the Netherlands' eurosceptic and fiercely anti-Islamic populist Geert Wilders stumbled Thursday, on the first day of voting on the continent.
His Party for Freedom scored just 12.2 percent of the vote on Thursday, down from 17 percent in 2009, exit polls showed.
Meanwhile in France, a survey forecast a Sunday landslide for the anti-immigration, populist National Front, with 23.5 percent of the vote.
Some 400 million Europeans are eligible to vote in the polls, spread over four days in the EU's 28 member states, and which come as the bloc struggles for relevance in the aftermath of the eurozone crisis and grapples with the chaos on its eastern borders.
- Bucking eurosceptics -
Russia's annexation of Crimea has spooked many eastern European countries that were dominated by the Soviet Union for much of the 20th century.
Having anchored their security in the EU and NATO following the fall of the Iron Curtain, most of eastern Europe is expected to back pro-EU parties in the polls.
"The crisis in Ukraine may... push some voters to back mainstream parties and eschew those of a eurosceptic bent," Vit Benes, from the Prague-based Institute of International Relations, told AFP.
Fuelling that trend is the fact that "eurosceptic parties like the National Front in France or Britain's UKIP are pro-Putin," he said, referring to Russia's president.
Only Hungary, which votes Sunday, has a strong eurosceptic party -- the far-right Jobbik.
Dubbed "neo-Nazi" by the European Jewish Congress and shunned even by the far-right National Front and Austria's Freedom party for its extremism, Jobbik has emerged as the second strongest political force in Hungary, with polls showing support of around 17 percent.
In the Czech Republic, which previously eyed EU controls with unease, two governing pro-EU parties are set to split 51 seats, with the populist ANO party poised for victory ahead of the leftwing Social Democrats.
"The euroscepticism of Vaclav Klaus has dissipated," Prague analyst Jiri Pehe said of the ex-president who was among Europe's most vehement EU haters over his decade in office until 2013.
Regional heavyweight Poland is among the most enthusiastic EU supporters. A recent Pew Research Centre poll showed 72 percent favoured the EU.
Europhilia is particularly pronounced in the Baltic states, which were annexed by the Soviet Union after World War II, and now fear a resurgent Russia.
- Political 'earthquake' -
But in Britain, UKIP's rise has rocked the political establishment, as a party without a single seat in its national parliament heads into the European election ahead of the main opposition Labour Party, opinion polls showed.
The party's rise was seen as a factor in Conservative Prime Minister David Cameron's pledge to hold a referendum on Britain's EU membership in 2017.
Farage has rejected claims his party was racist and said he wanted to cause a political "earthquake".
"If we get what we like, things will never be quite the same again," he told reporters, with UKIP expected to increase its current nine seats.
Former French president Nicolas Sarkozy insists reform of the EU was necessary to halt the rise of populist parties.
In an opinion piece published Thursday, Sarkozy urged the end of Europe's visa-free Schengen area and the creation of a Franco-German economic bloc at the heart of the eurozone.
Anger over EU-imposed fiscal policies was expected to see a boost for anti-austerity candidates from Ireland's Sinn Fein.
Latvia, Malta and Slovakia hold their polls on Saturday, while the rest will vote Sunday.