Israel's former ambassador to France has expressed his dismay at support given by French Jews to Marine Le Pen, leader of the Front National (FN).

Ms Le Pen won almost one in 5 votes in Sunday's first round presidential election.

One in five voters in the French presidential elections backed the candidate of the country's far right National Front Party.

Marine Le Pen was in third place after Sunday's first-round election. A run-off will be held between the two leading candidates, Socialist challenger Francois Hollande – currently the frontrunner – and incumbent Nicholas Sarkozy.

Last month's attacks in which a jihadist shot four people at a Jewish school in Toulouse have changed the focus and, quite possibly, the outcome of the French presidential election.

Mohamed Merah, who also shot three soldiers in a separate attack and was killed following a 32-hour siege, had only one alleged collaborator - his brother.

French police may have thwarted a plot to kidnap a Jewish magistrate last week.

According to AFP, the raid on 16 suspected Islamists last week has led investigators to plans to target members of the country's Jewish community.

In the past few years there has been a wave of acclaimed French novels about Vichy and the Holocaust - Irène Némirovsky's Suite Française, Jonathan Littell's The Kindly Ones, Tatiana de Rosnay's Sarah's Key and now Fabrice Humbert's The Origin of Violence, winner of the first-ever French Orange Prize.

As ever, as the dust settles, the facts become clearer. In the case of Mohamed Merah, the killer of three Jewish children, a rabbi and three soldiers in France earlier this month, the questions have become sharper too.

Though local authorities have been praised for their handling of the bloody dénoument of Merah's short-lived terrorist career, many doubts remain.