STRASBOURG (AFP) - The European Parliament on Tuesday lifted immunity for French National Front leader Marine Le Pen, opening the way for her to face charges for likening the sight of Muslims praying in the street to Nazi occupation during World War II.

The far-right leader, who was present for the vote along with her father and National Front founder Jean-Marie Le Pen, said ahead of the vote by lawmakers that she was a "dissident".

Ms Le Pen also said she was confident she would win any trial.

Prosecutors in Lyon in central France are investigating Ms Le Pen for alleged incitement to racial hatred over the remarks she made in a speech to National Front supporters in 2010.

In the speech she denounced the holding of Muslim prayers in the streets of France - where a dearth of mosques has forced many to pray outside - saying: "For those who like to talk about World War II, to talk about occupation, we could talk about, for once, the occupation of our territory."

"There are no armoured vehicles, no soldiers, but it is an occupation all the same and it weighs on people."

First elected to the European Parliament in 2004, Ms Le Pen won 18 per cent of the vote in the first round of France's presidential election in 2012, the party's highest-ever score.

The Parliament's judicial committee last month voted with an overwhelming majority in favour of lifting her immunity - a vote that French lawmakers abstained from to avoid any accusation of a political settling of scores.

As with many national parliaments, members of the European Parliament enjoy immunity from criminal and civil liability for opinions expressed as part of their duties.

That immunity has been revoked dozens of times in the past.

Mr Jean-Marie Le Pen had his European Parliament immunity revoked in 1998 when he said that Nazi gas chambers were "a detail" in the history of World War II.

He has several convictions for racism and anti-Semitism.

The National Front's third European Parliament member, Mr Bruno Gollnisch, was also in the chamber in Strasbourg on Tuesday.

He complained that Ms Le Pen had not been able to address lawmakers, but was quickly rebuffed by European Parliament vice-president Gianni Pittella who said that the rules stipulated she could have spoken to the judicial committee.

Ms Le Pen was asked to appear three times but did not do so.

"The person concerned has not been able to express herself. This procedure is like the old Soviet Union rather than one fitting with the rules of this house," Mr Gollnisch said.

The independent watchdog site VoteWatch Europe said Ms Le Pen is one of the least active European lawmakers.

She has never authored any report or resolution and her public speeches in the chamber are extremely rare.

In brief remarks earlier on Tuesday, Ms Le Pen addressed the scandal over alleged United States' spying of EU offices, saying it showed the European Union was "submissive" towards the US.

She also said a planned EU-US free trade agreement would be "deadly" for Europe's economy and civil freedoms.

With a year to go before the next European elections, the National Front is neck and neck with the French Socialist party and the centre-right UMP with 21 per cent of voting intentions, according to a survey by the Ifop polling agency.