Elections in 27 countries for the European Parliament ended on Sunday, with early projections giving far-right parties a strong showing, a result that, if confirmed, would amount to a powerful gauge of voter dissatisfaction and a stinging rebuke for the political mainstream.
The balloting indicated that the prevailing winds had grown decidedly chill for Europe’s political establishment. The results are likely to make it harder for the European Parliament to form majorities to pass laws, and would render negotiations over divisive issues even tougher. More broadly, they underscored that the momentum of the far-right forces that have been expanding their challenge to centrists over the past decade had yet to crest.
The projected outcome did not bode well for Europe’s centrist leaders and their parties, including in France and Germany, the continent’s biggest powers that are considered the engine of Europe’s experiment in pooling national sovereignty.
The results were especially crushing for President Emmanuel Macron of France, who on Saturday night hosted President Biden at a state dinner in Paris. Mr. Macron’s Renaissance party was poised to finish with about half the support of the far-right National Rally of Marine Le Pen, which was on track to secure more than 30 percent of the vote, according to projections based on preliminary vote counts.
The result may now leave Ms. Le Pen, whom Mr. Macron has derided as a threat to the values of the French Republic, in her strongest position yet to challenge the French mainstream in presidential elections three years from now, when Mr. Macron, who is term limited, must step aside.
The far-right Alternative for Germany party, or AfD, officially labeled a “suspected” extremist group by the German authorities, also showed strongly.
Projections gave the party about 16 percent of the vote. The projected result placed AfD behind the mainstream conservative Christian Democratic Union, but ahead of Chancellor Olaf Scholz’s Social Democrats, making it the country’s second-ranking party.
Right-wing parties now govern alone or as part of coalitions in seven of the European Union’s 27 countries. They have gained across the continent as voters have grown more concentrated on nationalism and identity, often tied to migration and some of the same culture-war politics pertaining to gender and L.G.B.T.Q. issues that have gained traction in the United States.
The strong far-right showing was likely to reverberate even in the United States, where it can be expected to hearten kindred political forces loyal to former President Donald J. Trump as he seeks a return to office in the general election on Nov. 5.
Other factors contributing to the right’s rise have been lingering anger over Covid-era policies and the inflation that grew in the wake of the pandemic and as a consequence of the war in Ukraine, which pushed Europe to turn away from cheap Russian energy.
Part of the far right in the European Parliament is pro-Russia and wants to push for a swift peace deal with Ukraine on Russia’s terms. Their voices could influence what has so far been solid E.U. support for Kyiv in the form of billions in funding for arms and reconstruction, as well as a path to E.U. membership.
European Union leaders have already watered down environmental policies and overhauled the bloc’s migration policies to address concerns by traditional conservative and further-right voters, but the electoral success of more radical right-wing parties could lead to still more changes.
Fresh, firmer figures based on actual votes counted were expected to be made public later Sunday evening.
Aurelien Breeden contributed reporting from Paris.
