Voters stampede to elect Socialist Party leader

The runaway favourite François Hollande comfortably topped the poll in France's Socialist presidential primary last night but fell short of the numbers needed for certain victory in the run-off next weekend.

Mr Hollande took 39 per cent of the vote and the Socialist party leader, Martine Aubry, scored 30 per cent. The left-wing candidate, Arnaud Montebourg, confounded predictions by coming in third with 17 per cent, relegating the failed 2007 presidential candidate, Ségolène Royal, to a poor fourth place.

Since the cautious Mr Hollande, 57, is disliked by harder left voters, the result of the two-candidate second round next Sunday could balance on a knife's edge. Although Mr Hollande should still win, he may be denied the overwhelming mandate to challenge President Nicolas Sarkozy next spring that he, and many other Socialists, had hoped for.

In every other respect, yesterday's election was a remarkable success for the Parti Socialiste. More than 2 million people – 10 times the party membership – cast a ballot in the first presidential primary to be thrown open to all-comers. Interest in the so-called "citizens' primary" was so great that the Socialist party's election website crashed in mid-morning. Tens of thousands of extra ballot papers had to be printed in Paris. In many towns and cities, voters queued patiently for more than an hour.

To build momentum behind a centre-left candidate for the presidential elections next April and May, France's main opposition party decided last year to throw open its primary to any voter willing to pay one euro and sign a declaration of "left-wing values".

The party's acting first secretary, Harlem Desir, said last night that the turnout had "exceeded our most secret desires". He said the enthusiasm for the primary reflected France's "rejection" of Mr Sarkozy and a popular hunger for transparency and honesty in politics.

Opinion polls had suggested that Mr Hollande might win an even more emphatic victory. They failed to track the sharp rise in the popularity of Mr Montebourg, 48, who captured the angry mood of many left-wing viewers during TV debates by attacking globalisation and the "tyranny" of markets.

If Mr Montebourg's voters transfer next week to the traditional left-winger Ms Aubry, 60, rather than to the moderate Mr Hollande, the second round score will be neck and neck. Mr Hollande will have to scoop almost all of the disappointing 7 per cent won by his former partner, Ms Royal, and the 5 per cent that went to the right-wing "Blairist" candidate, Manuel Valls. The sixth candidate, Jean-Michel Baylet, took less than 1 per cent of the vote.

One celebrity voter was the former IMF head and former Socialist minister Dominque Strauss-Kahn. Until he was arrested in May on rape allegations, since dropped, DSK was favourite to win the Socialist primary and next year's election. After voting in Sarcelles, a town north of Paris where he used to be mayor, he told reporters that he had cast a ballot for his friend, Martine Aubry.