The scientist who predicted Donald Trump's US election victory has claimed far-right candidate Marine Le Pen could win the French election because of voter abstention.

French physicist Serge Galam has said the National Front leader could benefit from her hard-core following who will ensure they turn out to back her. 

By contrast, a substantial number of people who said they would vote for her rival may not actually go to the polls, he claimed.

Mr Galam, a researcher with the French National Centre for Scientific Research, said: 'Obviously nothing is done yet but her election is becoming very likely.

I'm taking a scientific view of this. She needs a turnout differential of about 20 per cent to win.' 

Only the two top candidates in the April 23 opener go on to the May 7 runoff. 

Current opinion polls put the two front-runners - centrist Emmanuel Macron and Le Pen - in the mid-20s, ahead of Socialist Benoit Hamon, his hard left rival Jean-Luc Melenchon and embattled Thatcherite Francois Fillon.

Mr Galam said that, unlike the other candidates, Le Pen might benefit from a committed voter base.

By contrast, many left-wing voters will be reluctant to back Fillon whose campaign has been dogged by the fake jobs scandal.

At the same time many conservative voters might refrain from voting for Macron because they regard him as a natural heir to President Francois Hollande.

Indeed Nicolas Sarkozy's former adviser Henri Guaino said he would rather 'go fishing' when asked to choose between Le Pen and Macron in the second round.