PARIS (AFP) - The frontrunner in the French left's primary to choose a presidential candidate, Francois Hollande, enjoyed a comfortable lead Sunday after around a quarter of votes cast were counted. Hollande had 56.48 percent of votes against Martine Aubry's 43.52 in the run-off, with 486,437 votes counted. Socialist Party leaders had predicted a turnout of around 2.8 million left-leaning voters. Barring a bizarre late upset, the vote put the 57-year-old lawmaker and former party leader on course to be confirmed as the Socialist Party candidate for next year's two-round presidential race in April and May. It also puts him in pole position to oust President Nicolas Sarkozy, as opinion polls consistently predict that the Socialist Party is on course to defeat the centre-right incumbent next year. The vote was also France's first US-style open primary - any elector who says he or she supports the ideals of the left could vote - and the big turnout could serve as a springboard for the campaign proper. Last Sunday, a bigger than expected 2.66 million voters turned out for the first round, which was won by 57-year-old lawmaker and former party leader Hollande, with only a narrow nine-point lead over Aubry. Polls closed at 1700 GMT and Socialist interim leader Harlem Desir, citing partial results, said turnout had increased by six percent. Reliable turnout figures and results were not expected until 9.00pm (1900 GMT). Voting in the southwestern town of Tulle, in his rural constituency, Hollande predicted a big turnout, dubbing this a "good sign". "The bigger the turnout, the clearer our victory will be and the greater our candidate's chance of winning in 2012. It is an important moment, a serious one, even if it's not the final moment. That will be May 6, 2012," he said.