The leader of a separatist party won the race to become mayor of Antwerp, Europe's second biggest port city, and vowed Sunday to use the power base to seek wider autonomy for Belgium's wealthy Dutch-speaking region of Flanders.

Bart De Wever's NV-A party made sweeping gains throughout northern Flanders and immediately called on French-speaking Belgian Prime Minister Elio Di Rupo to give more rights of self-rule to Flanders.

De Wever said "we want to give Flemings the government they want at all levels. That is why I call on Elio Di Rupo and the Francophone politicians. Take up your responsibility" and work for more regional autonomy.

He says he will work for even bigger gains for separatists at the 2014 national elections.

De Wever has been at odds with Belgium's economically ailing French-speaking Wallonia for years, saying he is fighting over the fate of the 6 million Flemings in the kingdom of 11 million.

With all but 2 percent of votes counted, De Wever was leading Antwerp's incumbent Socialist mayor Patrick Janssens 37.7 percent to 28.6 percent.

De Wever has made it no secret he is looking for national impact during the municipal elections. He has criticized French-speaking Socialist Di Rupo over tax policies he says tap too much money from Flanders.

"Your taxation government without a majority in Flanders is not backed by Flemings. Let us work together on a reform that gives Flemings and francophones the government that they deserve," De Wever said in his victory speech.

Di Rupo immediately dismissed the suggestion, saying there was no reason to change national policy. "These are municipal elections. Each is free to declare what he wants on an election night."

In municipal elections six years ago, the NV-A was a nascent party with few votes across northern Flanders, but by 2010 national elections it had become the biggest party in the region. Sunday's elections confirmed it.

"We not only do as well as our monster score of 2010," De Wever said. "We do even better, and no one could have expected this. It is incredible. It is a black-yellow Sunday," he said, referring to the colors of the Flemish flag.

Because of the fragmented nature of municipal elections, precise voter percentages were still hard to come by late Sunday, but the sweeping victory of NV-A was beyond doubt. Di Rupo's socialists also had strong results in several Francophone cities, including his home bastion of Mons.

After the 2010 elections, De Wever was the main reason that Belgium had the longest period without a government on record — at 541 days — because he sought extensive concessions for Flemish autonomy.

He failed and ended up in opposition against Di Rupo, a staunch defender of the Belgian nation-state.

While De Wever's NV-A surged on Sunday, the extremist anti-foreigner Flemish Interest party crashed. "We saw our voters flee to the NV-A," Flemish Interest lawmaker Gerolf Annemans said.

"Our city was the European base of the radical right wing for two decades. This era ends today," a triumphant De Wever said.

Moves toward separatism in the European Union have been getting a bigger stage during the continent's economic crisis. Spain's Catalonia is grousing that it has to pay for others in its crisis-hit country, and Scotland is seeking a referendum on breaking away from the United Kingdom.