To cries of “Long Live a Free Flanders” as he emerged to address supporters, New Flemish Alliance leader Bart de Wever, 39, declared the NVA winners before telling French-speaking voters: “Don’t be afraid. Have faith in yourselves.”

De Wever’s party, which ultimately wants independence, won the largest share of the vote, some 29.5 percent based on about half of official returns in Dutch-speaking Flanders, and wasted no time in demanding radical reform of Belgium.

However, he stressed that the party “must assume our responsibilities” during horse-trading that will also centre on reform of the state’s finances.

He stressed that Flemish nationalists had to “extend a hand to francophones” to find a “structure that functions,” adding that “we need to change the state together.

He has allies in terms of his ultimate goal, though, with the far-right Vlaams Belang scoring 12.5 percent, and the De Decker list expecting to pick up about 3.7 percent.

“The challenge is enormous (but) the Flemish people have chosen change and we won’t let them down,” de Wever added.

He underlined: “It’s in no one’s interests to block (a deal).”

De Wever later told TV cameras that he will stand aside in talks seeking to nominate a new Belgian prime minister to replace current caretaker Yves Leterme.

“The job of prime minister for me is not important, the key is to get a deal.

“If it helps the francophones to trust us, I’m happy to make that sacrifice,” he added.

The favourite to take that post is Elio di Rupo, an openly homosexual leader of the Walloon Socialist party, who said his party had claimed a “fantastic success” in the parallel elections in the other two federal regions.

The socialists scored some 36 percent of the vote in both Wallonia and in the Brussels region, the country’s only officially bilingual area, VRT television projections showed awaiting official results.

Di Rupo said his party had a “considerable responsibility at a historic moment” for Belgium, observing that the majority Flemish had “manifestly” voted in large numbers for “institutional change.”

He said he would push for “a reform of the state that would guarantee greater prosperity for Walloons, the people of Brussels and Flanders,” Belgium’s larger and more affluent north.

Collectively, Walloon leaders are expected to seek guarantees that the Belgian welfare state, and its financing, will continue.

Didier Reynders, the outgoing francophone Belgian finance minister, accepted defeat but urged both Flemish and Walloons to come together “to stabilise this country.”

“There is a very serious constitutional crisis… but also a financial crisis” that had to be addressed, he underlined.

Belgium already has heavily devolved regional governments, divided along linguistic lines with these differences anchored in a financial gulf.

It has had four governments and three prime ministers since its last general election.

On Sunday, the NVA’s breakthrough came at the expense of Flemish Christian Democrats led by Leterme, whose five-party coalition broke up in April.

His administration will remain in charge of day-to-day affairs until negotiations, which could prove lengthy, are wrapped up — meaning he will assume the six-month rotating presidency of the European Union next month.

Voting is obligatory for the 150 parliamentary seats in the country of 10.5 million people, 60 percent Flemish, where no political party operates nationally.