The letter describes the FIE vote earlier this month to reinstate Russian and Belarusian fencers as a "catastrophic error" and accused the federation of "not fulfilling its duty of care for athletes, particularly Ukrainians".

It has been signed by 323 fencers, 286 of whom are still competing.

The letter has been copied to IOC Athletes' Commission chair Emma Terho and FIE Athlete Commission leader Rubén Limardo Gascon.

"With complete disregard for athletes' voices, you have permitted both Russia and Belarus back into FIE tournaments as well as a suspected tournament hosted on Russian soil," the letter says.

A paragraph specifically asks the IOC President, a team Olympic fencing champion at Montreal 1976, for action.

"We call upon you in your leadership capacity at the IOC to uphold your recommended suspensions of the Russian and Belarusian Fencing Federations and National Olympic Committees, and ensure the FIE adheres to your guidelines," it says.

The FIE vote means competitors from the two nations can take part in competitions from the beginning of April.

"This is an apparent break of the IOC's position and once again exposes Russian interests outweighing the voice and rights of athletes, especially those from Ukraine," the letter continues.

"You have chosen Russian and Belarusian interests over the rights of athletes, notably Ukrainian athletes, and by doing so, you are failing to support the very people your organisations are meant to support."

Last year, the IOC recommended a ban on Russian and Belarus competitors from taking part in all international competitions following the invasion of Ukraine.

However, it has now scaled back and is exploring ways for them to be able to compete neutrally.

Bach has insisted that politics and the actions of Governments should not impact an athlete, with the matter the key item on the agenda at an IOC Executive Board meeting which is starting today.

"Russia's aggression not only violates the norms of international law but also the fundamental values of Olympism," the letter adds.

The letter has been backed by Global Athlete and the German organisation Athleten Deutschland, from Bach's home country.

"Because of this passivity and irresponsibility on the part of the associations, it is once again the athletes who are being burdened with responsibility and who are being urged to make individual decisions about boycotts," Athleten Deutschland international sports policy adviser Maximilien Klein told Deutsche Presse-Agentur.

"The athletes would have preferred a different decision by the FIE," German fencing team spokesman Leon Schaefler added.

Germany finished second in the team event at the FIE Sabre World Cup in Budapest last weekend, the last competition before the Russian and Belarusian fencers are set to return.

An FIE World Cup foil event scheduled for May in Tauberbischofsheim, the town where Bach grew up, has already been cancelled as a result of the FIE decision.

But the German teams seem set to compete in other FIE Olympic qualification events, even if Russian and Belarus athletes do participate.

"If we don't compete, we would make it even easier for the Russians to get to the Olympics, the pro-Russia decision was not in the hands of the athletes," Schlaffer said.

He insisted that if individual athletes did decide to boycott, there should be no sanctions against them.

"The athlete must not be disadvantaged and thrown out of the squad," he said.

"This must not happen and it will not happen, the association promised that."

insidethegames has asked the IOC and FIE for comment.

The full letter can be read here.