Conservative lawmakers and politicians from Europe plan to attend the inauguration of President-elect Donald J. Trump. But the European contingent is also expected to include leaders of some parties that are on the right-wing fringes in their countries or have only recently begun to gain greater acceptance at home.

Many European politicians who flocked to Washington share the anti-immigrant fervor of Mr. Trump.

The leader of the European participants is Italian Prime Minister Giorgia Meloni, according to her official program. Ms. Meloni, a conservative, was one of the first leaders to visit Mr. Trump at Mar-a-Lago after his election on Jan. 4.

Ms Meloni, who is trying to stem the flow of migrants to her country, is seen as one of Europe’s strongest leaders and her supporters hope she will emerge as Mr Trump’s privileged ally in Europe.

The most notable absence is Hungarian Prime Minister Viktor Orban, one of Mr. Trump in Europe. Despite being highly regarded by many American conservatives as an ideological beacon, and Mr. Praised by Trump as “fantastic,” Hungary’s proudly illiberal leader was not invited to attend, according to a Facebook post by Zoltan Kovacs, Hungary’s secretary of state for international communications.

“To be crystal clear: Viktor Orbán will not participate in the event. President Trump’s team — in keeping with tradition — did not invite any foreign heads of state or government,” said Mr. Kovacs.

That is obviously not true. Mr Trump went out of his way to break with tradition and invite foreign leaders to attend, including Xi Jinping of China. (Mr. Xi sends the country’s vice president.)

Here are some of the Europeans who plan to show up

Éric Zemmour, who was convicted in France for inciting racial hatred, announced that he was invited to the inauguration. Mr. Zemmour has written bestsellers decrying the supposed decline of a nation whose Christian roots are being undermined by Muslim immigrants and their descendants.

Former television expert, whose race for the French president in 2022 was inspired by Mr. Trump’s campaignhe wrote on X, “The wind of liberty that blows through the United States will soon blow through France.”

Mr. Zemmour won just 7 percent of the vote in the 2022 presidential election, and his party has only one EU-level MP — Sarah Knafo, Mr. Zemmour’s partner, who plans to attend the inauguration with him.

France’s much more powerful nationalist, anti-immigrant party, the National Assembly, said it was sending a delegation, but neither Marine Le Pen, the party’s longtime leader, nor Jordan Bardella, its current president, would be coming.

While Mr. Trump’s anti-immigrant message resonates with the National Assembly, which is considered far-right in France, his subversive approach to politics is at odds with the party’s multi-year and increasingly successful efforts to cast a more extreme image.

Mr. Bardella said CNews television last week that he doesn’t understand the “fashion” of racing “to take a picture in front of Donald Trump during his inauguration speech.”

The contingent of Germans planning to attend the event includes a representative of the main conservative party — Jürgen Hardt of the CDU/CSU, who is leading in the polls for the upcoming German elections. But a member of Alternative for Germanyor AfD, parts of which are classified as right-wing extremist of the German government, is also expected to be there.

AfD’s representative will be Tino Chrupalla, its co-leader, and not Alice Weidel, the candidate for chancellor in the February elections. Elon Musk, a billionaire ally of Mr Trump, recently held a friendly interview with Ms Weidel on his social network X, giving the AfD a platform long denied by German media and politicians. Mr. Musk endorsed Ms. Weidel in the election.

Among the high-ranking British guests expected are former prime minister Liz Truss, who resigned after less than two months in office over a budget plan that rocked financial markets, and Nigel Farage, who leads the country’s insurgent, populist and anti-immigrant Reform UK party.

Mr Farage is a long-time ally of the president-elect and backed his campaigns for the White House in 2016 and 2020, as well as last year.

While in Washington, Mr Farage may have a chance to try to mend his ties with Mr Musk, who was a supporter but recently turned on Mr Farage. The spat began over Mr Farage’s refusal to repeat Mr Musk’s demand that the far-right agitator be given more criminal convictions be released from prison.