Far-right presidential candidate Marine Le Pen called for France to instantly reinstate border checks and expel foreigners who are on the watch lists of intelligence services on Friday, in the wake of the Paris terror attack.

It came as questions were raised as anger rose about how the suspected Champs-Elysées gunman, Karim Cheurfi, came to be released after being questioned in February over threats to kill police officers.

The Front National leader was not the only one to issue stern pledges on the final day of campaigning ahead of Sunday's closely-fought first round vote, in which she and centrist Emmanuel Macron are polling as frontrunners.

François Fillon, the conservative candidate who also has a tough discourse on security, said the fight against "Islamist totalitarianism" should be the priority of France's next president.

The gunman who shot dead a policeman on the Champs Elysees in Paris in an apparent Isil-inspired terror attack before being killed was named as French national Karim Cheurfi.