French far-right leader Marine Le Pen has refused to attend a summons by judges over allegations of misuse of European Union funds, according to her lawyer.

Marcel Ceccaldi said on Friday Le Pen had told the judges she would not attend before the end of the presidential campaign, to be held in two stages in April and May.

"Of course, she won't go," Ceccaldi said, citing Le Pen's parliamentary immunity.

A day earlier, EU politicians lifted Le Pen's EU parliamentary immunity on Thursday in a separate case involving tweeting pictures of violence by the Islamic State of Iraq and the Levant (ISIL, also known as ISIS).

Florian Philippot, a vice president of Le Pen's National Front Party, told French broadcaster LCI that Le Pen "herself requested a judicial investigation be opened more than a year ago ... and they waited until a year later, the presidential campaign, to do it".

"It's a bit much ... so, she'll respond after [the elections]," he said.

'Political interference'

Le Pen was called in for questioning for wrongfully claiming aides' salaries from the European Parliament.

She has already seen her earnings as a member of the European Parliament cut in connection with the case.

The far-right leader has denounced the legal proceedings against her as political interference in the election campaign, where she is the leading candidate.

She is expected to win the first of the two election rounds, but likely to lose in a runoff, according to polls, which also show that her legal battles seem to have little effect on her supporters.

Le Pen's immunity has been lifted before, in 2013. She was prosecuted in 2015 for "incitement to discrimination over people's religious beliefs", for comparing Muslims praying in public to the Nazi occupation of France during World War II.

Prosecutors eventually recommended the charges be dropped.