“I stood up from where I had been sitting and just fainted,” Fichot told This Week in Asia. “I think I blacked out for maybe five or six seconds, but when I came around, the little finger on my right hand was very badly bent.”

Two supporters took Fichot to a hospital, where X-rays confirmed a “complicated fracture” that might require surgery, he said.

Any procedure will be made even more complex by Fichot’s continued determination not to eat until he is able to see his children.

Even before he collapsed, Fichot had noticed some physical changes after so long without food. He says he becomes “very dizzy” when he stands up and is easily out of breath.

Yet he remains determined to see his campaign through, despite pleas from friends and family on social media to halt it.

“I am the master of my own destiny and I am fighting for the rights of my children,” said Fichot, who is originally from a town close to Marseille in southern France and has been a resident of Japan for 15 years. “I will stop if my children’s rights are respected and I choose to stop. Not before.”

French father of abducted children on hunger strike near Japan’s Olympic Stadium

He said he was driven to his extreme course of action after every other avenue to regain access to his children or even confirm that they were safe was blocked.

Appeals to the Japanese courts to see his six-year-old son Tsubasa and daughter Kaeda, now four, have been rejected since their mother disappeared without warning from the family home in Tokyo.

He has not been able to establish any contact with them since, although the courts have insisted that he continue to pay child support.

Fichot has appealed his case to the French government, the European Parliament and the United Nations Human Rights Council, while a civil case is ongoing in French courts, but he said he could “no longer sit by and do nothing”.

Japan does not legally recognise joint custody of children whose parents have separated, with courts usually siding with the mother.

Courts do not enforce visitation rights to children by the other parent and there are an estimated 150,000 children who lose contact with one parent every year in Japan.

In a joint statement, the two leaders vowed to “step up dialogue” on the plight of children of international marriages.

While Macron did not visit Fichot, an official was dispatched in an effort to convince him to call off his hunger strike. The official said change could only be achieved through diplomacy and that Japan “does not respond well to confrontation”, Fichot said.

In a message posted on his Facebook page, Fichot expressed his anger at his government’s failures.

“France has an obligation to protect its nationals, whether in France or abroad,” he said. “The reaction of the French authorities recently shows their lack of will to fulfil their roles in order to favour economic relations and at the expense of our children.”

Fichot compared the present French government to the collaborationist regime of Vichy set up after Nazi Germany conquered the nation in 1940, saying there were those “who joined the resistance to defend individual freedoms and respect for the rights of the French people. The government has chosen its side and I have mine”.

Fichot’s lawyer has contacted the legal representatives of his wife, to whom he is still married, but she has declined to respond.

A petition on the Change.org website has attracted more than 6,200 signatures and hundreds of expressions of support, while Japanese media has begun to cover Fichot’s story.

Fichot said he felt physically changed by his hunger strike and was aware that continuing to refuse to eat beyond 40 days could cause permanent damage to his health.