ANTWERP, Belgium — A far-right, “Islamophobic” party was set to make big gains last night in local elections across the Flemish speaking north of Belgium.

Before polls opened, the Vlaams Belang, or Flemish Interest Party, was predicting that it would win nearly 40% of all votes cast in Antwerp. The port is an historic city of some 450,000 people, rocked by rising racial tensions, including the double-murder of a toddler and her African nanny.

The party’s leaders stood at the 2000 local elections under the banner of the Flemish Bloc, drawing 33% support in Antwerp. But the bloc was declared illegal in 2004. The party emerged under a new name within days.

For the past six years, it has been kept out of power in Antwerp by a “rainbow coalition” of parties from across the political spectrum, whose only function is to deny Vlaams Belang office.

In a bold move, Vlaams Belang declared that it was expecting significant support from Antwerp’s 20,000 strong Orthodox Jewish community, despite its links with Belgium’s Nazi occupiers in World War II.

The party has softened its once combative, anti-immigrant rhetoric for this election, adopting the slogan “Secure, Flemish, Livable,” and stressing issues like fighting street crime.

The party’s prospective mayor in Antwerp, Filip Dewinter, used the term “Islamophobia” in an interview with an American Jewish magazine last year to describe Vlaams Belang’s determination “to stop the spread of Islam in Europe.” The party has called for strict limits on immigration; limits on the number of mosques in Flanders; rules compelling immigrants to learn to speak Dutch and study Flemish culture, and curbs on state benefits for jobless immigrants.

Mr. Dewinter, 44, estimates that illegal immigrants comprise about 6.5% of the city’s population. In all, about 50,000 of the total population is Muslim, most of them Moroccan and Turkish. However, Orthodox Jewish residents packing the streets of Antwerp’s diamond-trading quarter scorned the idea that Vlaams Belang would win up to a third of their community’s votes, as Mr. Dewinter said last week.

Wearing Orthodox black suits and Homburg hats, the men were carrying palm fronds in honor of the feast of Sukkot, celebrated this weekend. That festival meant it was forbidden for Jews to cast their votes, Jeremy Sulzbacher said, unless they had organized a proxy vote. “Vlaams Belang doesn’t convince Jewish people,” he said.

“Once they’ve finished with the Muslims and the North Africans, who will they start on next? They’ll start on us, the Jews.”