A group of European politicians has backed a petition to revoke Marine Le Pen's parliamentary immunity as she undergoes investigation over a series of gruesome photos of Islamic State killings that she tweeted in 2015.

Members of the Legal Affairs Committee met on 28 February to vote in favour of the request by French investigators.

Eighteen MEPs voted in favour while the remaining three opposed lifting her immunity. The subject is now expected to go before the EU parliament on 2 March.

If left unprotected by the assembly, prosecutors will be able to charge the National Front (FN) leader for posting three graphic images of Isis executions on Twitter.

Le Pen had tweeted the images after an argument with a journalist who compared the FN to the Islamist terror group. One of the photos Le Pen shared was of the decapitated body of US reporter James Foley.

According to French law, distribution of violent images or those inciting terrorism is banned. Those found guilty can be sentenced to up to three years in prison and a fine of as much as €75,000 (£64,000).

The presidential candidate has so far used her position as an MEP to refuse attending police interviews. On Tuesday, she said that the legal committee vote was meant to target her political campaign.

"This only shows French citizens what the EU is, what the European Parliament is and that it's all part of the system that wants to stop the French people's candidate that I am," the anti-EU politician said as she called for a moratorium on judicial investigations until after the elections, according to France 24.

Florian Philippot, the vice president of FN, also spoke out in defence of his party chief. "Showing and naming the horror of Islamism allow us to fight against it," he told Reuters.

This is not the first time the 48-year-old far-right leader has had her immunity lifted. Following the revocation in 2013, she faced prosecution in 2015 with "incitement to discrimination over people's religious beliefs". The charges were in relation to a statement in which she compared Muslims praying in public to the Nazi occupation of France during the Second World War. Charges were later dropped.