Le Pen, who has been in frail health for some time, co-founded and led the National Front (FN) and in 2002 stunned France by making the run-off ballot in presidential elections.

His daughter Marine took over the reins of the party, renaming it the National Rally (RN) and seeking to move it toward the political mainstream, even as opponents accuse it of being inherently racist.

Jean-Marie Le Pen has been placed by a court outside Paris “under a regime of judicial protection”, the RN’s deputy leader Louis Aliot said.

The ruling, issued after medical tests, will allow his children to make decisions in his name. Such rulings are issued in France when the health of a person declines to the point they may need assistance to make decisions.

According to several of those close to him, Jean-Marie Le Pen’s health has declined significantly since he suffered a heart attack in April 2023.

The move also raises questions over whether Jean-Marie Le Pen will be able to stand trial alongside his daughter and two dozen others from Sept 30 on charges they used European Union funds to finance party activities in France.

They are accused of using EU parliamentary funds to pay for assistants who in fact worked for the RN. The party denies the charges.

“I think the court will have to decide that he can neither appear at, nor testify, nor participate in this trial,” Aliot said. A decision on his participation must be announced at the beginning of July.

The trial will also be a crucial moment for Marine Le Pen, who is widely expected to make a fourth bid for the presidency in 2027, with analysts saying she has her best chance yet of winning the Elysee Palace.