The French far-right presidential hopeful Marine Le Pen and a slew of fellow National Rally (RN) chiefs will go on trial on Monday over allegations they embezzled money from the European parliament with fake jobs.

For Le Pen, the hearings risk overshadowing a record performance in July’s snap parliamentary poll that handed the RN 126 seats – enough to sway prime minister Michel Barnier’s shaky minority government.

Going on trial in Paris are: the RN party itself, nine former MEPs including Le Pen and party vice-president Louis Aliot, spokesperson Julien Odoul – one of nine former parliamentary assistants – and four RN staff.

First flagged in 2015, the alleged fake jobs system at the RN covers contracts for parliamentary assistants between 2004 and 2016.

Prosecutors say the assistants in fact worked exclusively for the party outside parliament.

Many were unable to describe their day-to-day work and some had never met their supposed MEP boss or set foot in the parliament building, it is alleged.

A bodyguard, a secretary, Le Pen’s chief of staff and a graphic designer were all allegedly hired under false pretences.

“Could I come to Strasburg tomorrow to see how a session works and get to know Mylène Troszczynski who I’m under?” Odoul wrote to Marine Le Pen in 2015 – four months after his contract as a parliamentary assistant to Troszczynski had begun.

“Yes, of course,” she replied.

The misuse of public funds charges bear maximum penalties including a €1m (£830,000) fine, 10 years in jail and a 10-year bar from public office – potentially fatal to 56-year-old Marine Le Pen’s hopes of claiming the French presidency on her fourth try in 2027.

The party has for years called the investigation a form of “persecution” and political abuse of the justice system.

“Every time the party or its leaders are attacked, it lets them cast themselves as the victim,” said political scientist Nonna Mayer, of Sciences Po university in Paris.

Such a high-profile case is a rare obstacle to Le Pen after years of smooth sailing.

The RN has capitalised on the unpopularity of the French president, Emmanuel Macron, after he successfully cast the 2017 and 2022 presidential elections as a straight choice between himself and the far right.

A shock first-place RN result in the EU elections in June prompted Macron to call snap elections – a gamble that led to conservative Barnier’s uncomfortable minority coalition.

Barnier could be toppled at any moment if the left NFP alliance and the RN join forces in forcing a vote of confidence, putting Le Pen in a kingmaker role.

Polls show the former protest party also enjoys increasingly committed voter support.

One RN lawmaker told AFP that “when I don’t see Marine worried, I’m not worried” ahead of the trial.

University of Tours political scientist Sylvain Crépon told AFP that historically, “scandals in other parties work in favour of the RN, but scandals at the RN don’t benefit other parties”.

Le Pen told Le Parisien in mid-September “we are guilty of nothing”.

Her lawyer Rodolphe Bosselut declined to comment before the trial, set to last until 27 November.

The RN, formerly known as the National Front (FN) “don’t like Europe. The only thing they like is the European Union’s money,” said Patrick Maisonneuve, representing the European parliament as a co-plaintiff.

Prosecutors say Le Pen and her father, former party leader Jean-Marie, both signed off on a “centralised system” that picked up pace in 2014, when the FN’s Brussels ranks swelled.

Now 96, Jean-Marie Le Pen will not appear in court for health reasons.

Several people have testified about a 2014 meeting that one said discussed a clear “fake jobs” structure.

Evidence against the party includes contracts for periods as short as a single day to exploit spending allowances.

One message from the party treasurer, Wallerand de Saint-Just, warned about its disastrous finances, writing “we won’t get out of this without making significant savings thanks to the European parliament”.

EP authorities say the legislature was embezzled to the tune of €3m (£2.5m). The RN has already paid back €1m – which it insists is not an admission of guilt.