A former Nomura banker who quit his job to stage a hunger strike close to Tokyo’s Olympic stadium expects his health to be dangerously compromised by the time world leaders gather for the games’ opening ceremony next week.

Vincent Fichot, a 39-year old French national and once high-flying derivatives specialist, began his hunger strike last week in an “all or nothing” bid to secure access to his young children.

Speaking to the Financial Times, Fichot said he hoped his hunger strike would prompt action by Emmanuel Macron, France’s president, who is due to attend the Olympics opening ceremony on July 23.

By the time the Olympic torch is lit, said Fichot, who has sold his central Tokyo property and lives on a yoga mat outside Sendagaya station, his body will be entering an acutely dangerous state. That will leave Macron very little time to make good on a pledge to raise the case with Japan’s prime minister.

“It’s not despair. It is a calculated act. I may not be able to force Japan to do something, but I may be able to force France to do something on my behalf,” said Fichot. “They cannot let me perish here.”

Fichot has been joined daily by other parents — Japanese and foreigners — locked in a battle against a system they believe has stolen their children.

His protest, which is being staged a few hundred metres from the stadium for deliberate effect, followed a failed three-year battle with Japan’s court system and what many parents in a similar position have condemned as a needlessly antiquated policy.

Japan’s divorce and separation proceedings, which Fichot and others say are out of step with those of other developed countries, do not recognise the concept of joint custody.

That stance, experts said, combined with the overwhelming likelihood that courts will award sole custody to whichever parent happens to be caring for the children at the time of custody cases, creates incentives for one parent to “kidnap” their children ahead of a divorce.

Once the divorce is completed, the parent with the children is under no obligation to grant access. Informal support groups claim that tens of thousands of children have been unfairly kept from the other parent by the intransigence of the Japanese system.

Fichot, who was in the process of seeking a divorce, said he had no inkling when he left for work at Nomura’s Otemachi headquarters on August 10, 2018 that he would return to find his wife and children — at the time aged three and 11 months old — gone.

Apart from direct efforts to secure access to his children through the courts, Fichot has also lobbied supranational organisations, including the UN.

Last July, following Fichot’s campaigning, the European parliament adopted a resolution condemning the abductions and calling on Japan’s government to modernise its legal system and enforce international rules on child protection.