Party leader Marine Le Pen called on “those who fight for democracy” to “stand up for their principles” after judges withheld two million euros ($2.4 million) in subsidies granted to French political groupings.
“If tomorrow (far-left party) France Unbowed were in our situation, I would come to their defence,” Le Pen told BFM television.
She and other National Rally lawmakers are accused of using funds earmarked for parliamentary assistants when they were European Parliament MPs to pay for France-based staff over several years starting in 2009.
On Monday sources close to the inquiry told AFP that four more people had been charged last month.
They include Nicolas Bay, an MEP and top party leader, who was charged with breach of trust, and Le Pen's bodyguard Thierry Legier, who was paid in part with the EU parliament funds.
If convicted the party could be ordered to repay seven million euros.
Sources close to the inquiry say the two investigating judges worry the subsidies will be used instead to repay debts racked up by the party after a
series of recent financial setbacks.
But Le Pen argues that seizing the subsidies before any verdict has been reached is tantamount to a “judicial coup d'etat” that will bankrupt her party
She said the judges' move was “terrifying news for our country which will resonate beyond our borders.”
“What are people going to say about our democracy?”
Officials from several rival parties came to her defence on Monday.
“The principle in a democratic nation is nonetheless to make sure that a seizure doesn't threaten a party's very existence,” Socialist Party leader Olivier Faure told Europe 1 radio.
The party, known until recently as the National Front, has set up a website to collect donations from supporters.
It had expected to touch roughly 4.5 million euros in subsidies this year, proportional to the party's results in recent elections — Le Pen beat out candidates from several rival parties to face off against Emmanuel Macron in last year's presidential vote.
Such subsidies are common in European countries, which see them as a way of ensuring a level playing field while limiting the risks of political corruption or illegal funding.