Belgium's year-long political crisis deepened Thursday when Flemish separatists in its largest party rejected a make-or-break compromise, opening the door to snap elections that could split the nation.

Hopes for an end to a damaging 13-month impasse in language-divided Belgium came crashing when the Flemish N-VA rejected out of hand a compromise offered by French-speaking rivals, to serve as a basis for setting up a governing coalition.

"With the best will in the world I do not believe negotiations on the basis of this note can lead to success," said hardline N-VA leader Bart De Wever, referring to a platform for governance outlined by francophone Socialist leader Elio Di Rupo.

The country at the heart of Europe has been rudderless for more than year since general elections on June 13, 2010, failed to produce a workable coalition.

Di Rupo, whose Socialists garnered the second largest vote in the 2010 general elections and came on top in the French-speaking Wallonia region, had been asked in May by King Albert II to form a government.

Over the past year, which has earned Belgium the dubious record of the world's country longest without a government, the sovereign named a succession of negotiators to broker a coalition deal, but all returned to the palace empty-handed.

"We are close to an early election," political scientist Dave Sinardet told AFP. "If not we'll remain in this no-man's land, going round in circles -- but it can't go on for ever."

Recent polls show the N-VA, which last year garnered 28 percent of the vote in northern Dutch-speaking Flanders, upping its popularity to more than 33 percent.

At a news conference, De Wever notably blasted Di Rupo's proposed platform for failing to devolve enough power to the country's two main language-based regions -- Dutch-speaking Flanders and French-speaking Wallonia.

He also lashed out against a "tsunami" of extra taxes and said the Socialist had failed to cater to his liberal party's demands for labour market and social welfare reform.

But he said he was "not at all thinking of elections".

After releasing his platform Monday following weeks of painstaking talks with Belgian leaders, Di Rupo had said N-VA participation in a new coalition seemed imperative.

His platform called for massive cuts in public spending by 2015 and extra power to the regions.

He pledged to create a quarter of a million jobs and enforce a temporary wealth tax to reap 1.25 million euros up until 2015.

Turning to the divide between the country's 6.2 million Dutch speakers and 4.5 million francophones, the Socialist leader called for new devolution to regional and community authorities, which would be the sixth administrative reform in the country in 40 years.

Those institutions would receive an extra 17.3 billion euros, notably to run employment policies, and would be given greater powers to raise taxes.

After years of bitter inter-communal strife over the rights of French-speakers in districts ringing majority-French Brussels but located in Flanders, Di Rupo also offered to redraw constituencies, ceding ground to Flemish demands.

De Wever said the French-speakers were being granted too many rights.

Under Di Rupo's plan, Brussels would receive supplementary funds of 460 million euros to overcome its financial troubles.