When Nicola Procaccini was elected to the European Parliament six years ago, colleagues seemed to avoid stepping into elevators with him at the towering glass Parliament building in Brussels, he said. He belonged to a tiny, fringe party on the right of Italian politics whose hard-line stances on immigration were scorned.

“My hand would hang midair because they don’t shake hands with fascists,” Mr. Procaccini said in an interview, derisively characterizing how he thought his opponents saw him. Meanwhile, migrant rights activists were invited into the Parliament chamber and cheered.

Now those tables have turned, he said. “Those who told us our approach was racist, xenophobic, are slowly starting to say, ‘Well, maybe they’re a bit right,’” Mr. Procaccini said, noting that mainstream politicians are now embracing more of his party’s policies on migration.

Mr. Procaccini’s party, Brothers of Italy, is now very popular in Italy. Its leader, Giorgia Meloni, is the country’s prime minister. And Mr. Procaccini is a chairman of the European Conservatives and Reformists group, a big force in the European Parliament.

Across the political spectrum in Europe, leaders, right and left, are pushing a tougher line on undocumented migrants. The shift has not set off the same turmoil that President Trump’s immigration crackdown has stirred in the United States, but it is already being seen as entrenched and profound.

In nations across the European Union, centrists are joining staunch conservatives to roll back protections in an effort to make it easier to deport illegal migrants. Denmark’s “zero” refugee policy has become a model other leaders want to replicate. European Union officials are working on new rules that would help to send asylum seekers to third countries. The bloc struck a recent deal to deploy agents in Bosnia and Herzegovina, which is not an E.U. member, to better police borders.

Some of those ideas have previously met with criticism from European Union officials.

“There is now this really broad consensus among almost all political camps,” said Martin Hofmann, an adviser at the International Center for Migration Policy Development. “We will be tougher, we will be stricter.”

The shift has steadily built with the voter backlash that helped fuel nationalist, far-right and populist parties after Europe took in more than a million Syrians, Iraqis, Afghans and others seeking asylum a decade ago.

Migration picked up again, though less drastically, just after the peak of the coronavirus pandemic. But since then, the number of migrants arriving has fallen. They declined by about 20 percent in the first five months of 2025, after a sharp decline last year, according to preliminary data collected by Frontex, the European Union’s border agency. At the same time, expulsions have slowly increased.

But migration along some routes remains significant. Ursula von der Leyen, the president of the bloc’s executive arm, emphasized in a recent letter to political leaders that arrivals from Libya into Greece are surging, and said that Europe must “insist on strengthening border management.”

Mr. Hofmann said that because anti-immigrant sentiments are often a proxy for wider frustration with a perceived lack of opportunities, high costs of living and a loss of social status, a drop in migrant arrivals alone was unlikely to blunt the issue’s potency.

In his view, policies that seem to be working to stem immigration are likely to retain their appeal and continue to gain momentum. That includes offshoring asylum requests, which the European Commission is exploring.

Not long ago, when the British government proposed sending asylum seekers to Rwanda, the Council of Europe’s commissioner for human rights said the plan was another representation “of an ongoing trend towards externalization of asylum and migration policy in Europe,” which he said was “a matter of concern for the global system of protection of the rights of refugees.”

Now, the policy of offshoring asylum requests has become a signature of Ms. Meloni, who has tried to hold asylum seekers in Albania while their cases are processed.

Though Italian judges have blocked her effort for now, Ms. von der Leyen called it “an example of out-of-the-box thinking.” Now the European Union is seeking to redirect applicants to third countries while it works to streamline the deportation process for asylum seekers whose applications have been rejected.

The depth of the change was on full display last month when Mette Frederiksen, the Social Democratic, left-leaning Danish prime minister, stood alongside the staunchly conservative Ms. Meloni in Rome to support tougher migration rules.

Ms. Frederiksen, whose country has relatively few asylum requests, has for several years overseen one of Europe’s most restrictive policies. Others are now seeking to adopt a similar approach.

Chancellor Friedrich Merz of Germany, the center-right leader of Europe’s largest economy, this month called Denmark a “role model” on migration policy.

Ms. Meloni and Ms. Frederiksen presented an open letter in which they argued that the European Convention on Human Rights — the 75-year-old cornerstone for the protection of human rights in Europe — “posed too many limitations on the states’ ability to decide whom to expel from their territories.”

It was also signed by leaders from Austria, Belgium, the Czech Republic, Estonia, Latvia, Lithuania and Poland.

Ms. Meloni said at a news conference that the fact that the signatories belonged to different “political families” showed “how the topic is of great interest across different sensitivities.”

The underpinnings of the convention have already eroded with the shift on migration.

Deals with countries like Libya and Tunisia have helped slow the influx of migrants, said Camille Le Coz, the director of Migration Policy Institute Europe. But they have done so “at a huge human rights cost,” she said, such as when, in 2023, the Tunisian authorities dumped African migrants in a desert.

Germany has now instituted checks on its land borders, a step that opponents, including some of its neighbors, have criticized as undermining the commitment of E.U. members to free movement within the bloc.

The Polish government suspended asylum rights as migrants have massed at the border with Belarus, which is outside the European Union. Poland argued that the Russian and Belarusian officials were deliberately encouraging migration in a bid to destabilize Europe.

Some worry that the shift in tone around migration could harm newcomers who remain in Europe. In recent Polish presidential elections, the nationalist candidate won by running in part on a “Poland first, Poles first” tagline.

Magdalena Czarzynska-Jachim, the mayor of Sopot, Poland, a town on the Baltic seashore, said Sopot had long welcomed Ukrainian workers and, more recently, families who had fled the war in Ukraine. Ukraine is not an E.U. member.

She agrees that borders must be protected, but she also worries that recent messaging risks going too far, broadly characterizing immigrants as criminals. “Legal migrants are our neighbors,” she said. “They are not bandits.”

The shift in tone is striking even to those who have long been proponents of tougher measures.

A decade ago, when Australia barred migrants trying to enter the country by sea from resettlement and sent asylum seekers to Papua New Guinea, rights groups said the policy provoked human rights violations. The European Union was also critical, said Alexander Downer, an Australian former foreign minister.

“They used to give me lectures all the time about how naughty we were,” Mr. Downer said. “Von der Leyen has embraced it now.”