HVIDOVRE, Denmark — As right-wing populists surge across Europe, rattling established political parties with their hostility toward immigration, austerity and the European Union, Mikkel Dencker of the Danish People’s Party has found yet another cause to stir public anger: pork meatballs missing from kindergartens.

A member of Denmark’s Parliament and, he hopes, mayor of this commuter-belt town west of Copenhagen, Dencker is furious that some day-care centers have removed meatballs, a staple of traditional Danish cuisine, from their cafeterias in deference to Islamic dietary rules. No matter that only a handful of kindergartens have actually done so. The missing meatballs, he said, are an example of how “Denmark is losing its identity” under pressure from outsiders.

The issue has become a headache for Mayor Helle Adelborg, whose center-left Social Democratic Party has controlled the town council since the 1920s but now faces an uphill struggle before municipal elections Nov. 19.

“It is very easy to exploit such themes to get votes,” she said. “They take a lot of votes from my party. It is unfair.”

It is also Europe’s new reality. All over, established political forces are losing ground to politicians whom they scorn as fear-mongering populists. In France, according to a recent opinion poll, the far-right National Front has become the country’s most popular party. In other countries — Austria, Britain, Bulgaria, the Czech Republic, Finland and the Netherlands — disruptive upstart groups are on a roll.

This phenomenon alarms not just national leaders but also officials in Brussels who fear that European Parliament elections next May could substantially tip the balance of power toward nationalists and forces intent on halting or reversing integration within the EU.

“History reminds us that high unemployment and wrong policies like austerity are an extremely poisonous cocktail,” said Poul Nyrup Rasmussen, a former Danish prime minister and a Social Democrat. “Populists are always there. In good times it is not easy for them to get votes, but in these bad times all their arguments, the easy solutions of populism and nationalism, are getting new ears and votes.”

In some ways, this is Europe’s Tea Party moment — a grass-roots insurgency fired by resentment against a political class that many Europeans see as out of touch. The main difference, however, is that Europe’s populists want to strengthen, not shrink, government and see the welfare state as an integral part of their national identities.

The trend in Europe does not signal the return of fascist demons from the 1930s, except in Greece where the neo-Nazi party Golden Dawn has promoted openly racist beliefs, and also perhaps in Hungary, where the far-right Jobbik party backs a brand of ethnic nationalism suffused with anti-Semitism.

But the soaring fortunes of groups like the Danish People’s Party, which some popularity polls now rank ahead of the Social Democrats, point to a fundamental political shift toward nativist forces fed by a curious mix of right-wing identity politics and left-wing anxieties about the future of the welfare state.

“This is the new normal,” said Flemming Rose, the foreign editor at the Danish newspaper Jyllands-Posten. “It is a nightmare for traditional political elites and also for Brussels.”

The platform of France’s National Front promotes traditional right-wing causes like law and order and tight controls on immigration but reads in parts like a leftist manifesto. It accuses “big bosses” of promoting open borders so they can import cheap labor to drive down wages. It rails against globalization as a threat to French language and culture, and it opposes any rise in the retirement age or cuts in pensions.

Similarly, in the Netherlands, Geert Wilders, the anti-Islam leader of the Party for Freedom, has mixed attacks on immigration with promises to defend welfare entitlements.

Pia Kjaersgaard, the pioneer of a trend now being felt across Europe, set up the Danish People’s Party in 1995 and began shaping what critics dismissed as a rabble of misfits and racists into a highly disciplined, effective and even mainstream political force.

Kjaersgaard, a former social worker who led the party until last year, said she rigorously screened membership lists, weeding out anyone with views that might comfort critics who see her party as extremist. She said she had urged a similar cleansing of the ranks in Sweden’s anti-immigration and anti-Brussels movement, the Swedish Democrats, whose early leaders included a former activist in the Nordic Reich Party.

Marine Le Pen, the leader of France’s National Front, has embarked on a similar makeover, rebranding her party as a responsible force untainted by the anti-Semitism and homophobia of its previous leader, her father, Jean-Marie Le Pen, who once described Nazi gas chambers as a “detail of history.” Marine Le Pen has endorsed several gay activists as candidates for French municipal elections next March.

But a whiff of extremism still lingers, and the Danish People’s Party wants nothing to do with Le Pen and her followers.