REYKJAVIK, Iceland — Spain has Podemos. Italy has its Five Star Movement, and Greece its Syriza. Now, the populist insurgency sweeping through Europe is finding a foothold in Iceland, where the Pirate Party, with its pirate flag logo and anarchist leanings, is poised to make big gains in a general election on Saturday.

Iceland is one of the most prosperous, equitable and accountable democracies in the world, and has recovered strongly from the 2008 financial crisis. Even so, the nation’s political elite has been far from immune to public anger. Many voters are willing to risk it all by choosing the Pirate Party, which has spectacularly captured a chunk of the Icelandic electorate despite its niche origins as a hacktivist group.

“When I think about politics in Iceland, it makes me want to vomit,” Sigmundur Knutsson, 62, said in a deli as he ate fermented shark, an Icelandic delicacy. “It’s all about corruption among a very small elite,” he said. “There is something that is not right. Something smells bad.”

The Pirate Party, best known for its activism over copyright law and the protection of civil liberties, is expected to gain significantly in Saturday’s election. It is riding on a wave of anti-establishment fervor spreading across Europe and the United States, upending traditional politics and fracturing mainstream parties.