PARIS (AFP)--Socialist Francois Hollande will beat Nicolas Sarkozy in the second round of France's presidential election by 54% to 46%, according to the first opinion polls after Sunday's first round vote.

A survey by the Ipsos institute commissioned by French public television and the daily Le Monde predicted a majority of those who backed candidates eliminated in the first round would switch to the frontrunner in the runoff.

A separate poll by Ifop for Europe 1 radio and news weekly Paris Match predicted a similar margin, with Hollande winning by 54.5% to 45.5% for the incumbent.

The polls showed that the attitude of Marine Le Pen's supporters would be crucial. Le Pen was the surprise breakthrough of the first round, winning just short of 20% before being eliminated.

She has not yet said which way she will advise her voters to turn before the Hollande-Sarkozy runoff, but Ifop said that 48% of her backers would switch to Sarkozy and 31% to Hollande.

But a third poll by OpinionWay said that only 18% of Le Pen's supporters would back the Socialist, while 39% prefer the incumbent.