Editor's note: Explore Europe's main protest parties in the map above. Click on each country to find out more. Watch The Business View with Nina dos Santos, weekdays at 12pm CET, for more on the European elections. This interactive map may not work on all mobile devices.
(CNN) -- France's far-right National Front has won a nationwide election for the first time, as far-right parties across Europe caused a political "earthquake," with a string of victories in voting for the European Parliament.
The National Front, led by Marine Le Pen, notched up 24.95% of the vote in France, according to official estimates, well ahead of mainstream parties UMP and the Socialist Party. Le Pen said the win showed that people want to see change in Europe.
France's Socialist Prime Minister Manuel Valls said the result was "more than a warning. It is a shock, an earthquake."
Right-wing parties also gained ground in the UK, Denmark and Austria, according to projections posted on the European Parliament's official elections website.
Voters across Europe have been casting ballots for days in the parliamentary vote. There are 751 seats from 28 countries up for grabs.
With most of the ballots counted, provisional results indicate that left-center and right-center parties will still hold a majority of seats in the European Parliament, which plays a key role in shaping European laws and will weigh in on who the European Commission's next President should be.
But right-wing parties and other so-called Euroskeptic groups who oppose the European Union are gaining ground, said Simon Usherwood, an expert on European politics at the University of Surrey.
"I think what's really changed is you're seeing a lot more groups on the edges, particularly with the far right, who are going to be much more of a feature of the next five years of the parliament," he said.
So what does that mean?
"They don't have enough votes to stop legislation going through," Usherwood told CNN, "but what they will get, particularly on the far right, is the time for speaking in debates, the chairmanship of certain committees, which means that they're going to have much more of a platform on which they can sell their message to voters."
In France, which has 74 seats in the European Parliament, the National Front won 24.95% of votes, according to official estimates, coming in ahead of the center-right UMP, which scored 20.8%, and President Francois Hollande's Socialist Party, which came in third with 14%.
Even though the vote was for a regional legislative body, the potential impact on France's national political landscape was clear on Sunday. The results sparked stunned reactions from some French politicians and triumphant victory speeches from others.
PM Valls described the election as "a very serious moment for France and for Europe," noting that projections indicate that voters are skeptical of the European Union. "None of us can shirk their responsibilities," he said, according to a summary of his remarks posted on the French government's website.
Meanwhile, National Front leader Marine Le Pen said the results showed that French voters wanted more control.
"The sovereign people have proclaimed that they want to take back the reigns of their destiny into their hands. Our people demand one type of politics: politics of the French, for the French, with the French. They no longer want to be directed from outside," she said.
She said the vote shows that President Francois Hollande should dissolve France's parliament, where most lawmakers come from mainstream political parties.
Nearly 400 million Europeans were eligible to vote in the parliamentary elections. Turnout was just over 43%, slightly higher than it was during the last vote in 2009, Parliament spokesman Jaume Duch said.
"The clear message here is that people are unhappy with the way mainstream political parties have handled the economic crisis, and they're giving them a good kicking," said Petros Fassoulas, chairman of the pro-Europe European Movement.
Before the election, analysts predicted that protest parties were likely to triumph at the polls.
Those parties are demanding tighter border controls, nationalized decision-making and a dissolution of the currency union.
But they have little in common aside from a dislike of the Brussels bureaucracy, so it's difficult for them to find much common ground, Usherwood said.
"They can agree they don't like the EU," Usherwood said, "but they can't agree what they like and what the answer is."
CNN's Pierre Meilhan, Jim Bittermann, Ivana Kottasova, Jonathan Mann and Bryony Jones contributed to this report.