Front National leader Marine Le Pen has taken a sizeable lead over Nicolas Sarkozy in a new French presidential election poll.

The far-right leader had 29 per cent of the vote when pitted against Les Républicains’ former president, who was eight points behind, and held a 15-point lead over the Parti de Gauche’s Jean-Luc Mélenchon in the poll released by Ipsos.

It was one of five scenarios for the first round of France's 2017 presidential elections on 23 April, although one that did not include Les Républicains’ Alain Juppé – who remains strong favourite to succeed Francois Hollande as leader.

While Mr Juppé holds leads of between 4 and 7 per cent in three other scenarios including him, the results are likely to add to growing fears that the rise of global populism could see Ms Le Pen secure a surprise victory in the wake of the UK’s Brexit vote and Donald Trump’s US election win.

Marine Le Pen claims no difference between her policies and Ukip

Under the French election system, barring the unlikely possibility one candidate gains an overall majority in the first round vote, the two candidates with the most votes will contest a second and decisive round on 7 May.

Second round opinion polls have consistenly given Mr Juppé a significant lead over Ms Le Pen.

It came as leading French philosopher Bernard-Henri Lévy warned people had lost interest in whether politicians tell the truth, in a development he said could set the Front National on course to occupy the Élysée Palace.

“If Trump is possible, then everything is possible. Nothing, from now on, is unimaginable,” Mr Lévy told The Telegraph.

“As for Le Pen it is unlikely that she wins but it is possible, and that is partly because the people have lost interest in policy, instead focusing on personality.

“The people listen less and less to policy and they even seem less concerned about whether the candidates are telling the truth or not.

“They are more interested in the performance, in the theatrical quality of what is said than whether it is true. And as we know, a fascist can put on a very successful performance.”

The latest polls emerged as French conservatives voted in primaries on Sunday to choose their presidential nominee to face Front National candidate Ms Le Pen.

Seven candidates are competing for their position in the primaries and a second vote will be held next week to decide between the two frontrunners.

The three leading candidates are former president Mr Sarkozy and former prime ministers Francois Fillon and Alain Juppé - with many non-Republican voters hoping Mr Juppé wins as he has the best chance of beating Ms Le Pen.

French Prime Minister Manuel Valls said a Le Pen win next year could be “possible” and has warned of the danger of electing a far-right president, with many expecting Ms Le Pen to face a candidate from the centre-right if she makes it to the second round, given the current unpopularity of the ruling Socialist party.

Ms Le Pen has led the far-right Front National since 2011, when she succeeded her father Jean-Marie Le Pen, the party’s founder.

Since taking over the party, Ms Le Pen has made efforts to distance herself from her father’s openly antisemitic views, who has been convicted repeatedly for hate speech and contesting crimes against humanity, including describing gas chambers used to kill Jews in the Holocaust as a “detail” of history.

However, critics have branded Ms Le Pen a “fascist” and accused her of exploiting growing anti-immigration sentiment.

Marine Le Pen reacts to Trump victory

Jeremy Corbyn, who also appeared on the show, told Marr: “She uses this populism against minorities in order to get herself elected.

“The reality is she does not have an economic answer to the problems faced by the left behind communities in France any more than Ukip has an economic answer to the left behind communities in Britain.

“It’s only communities coming together with public investment that can deal with the fundamental economic injustices that are getting worse not better in Europe.”