Earlier this month, at a UIPM Executive Board meeting held after the Pentathlon World Cup in Budapest, two variations of the obstacle discipline were rubber-stamped for testing alongside fencing, swimming and the laser run following next month's World Cup Final in Ankara.

Choong, fellow Briton Kate Allenby - women's bronze medallist at Sydney 2000 - Ukraine's Rio 2016 men's silver medallist Pavlo Tymoshchenko, Australia's Alex Watson, the competition manager at Sydney 2000, and Denmark's Eva Fjellerup have written to long-serving UIPM President Klaus Schormann in a letter seen by insidethegames, demanding that comparative results from other proposals are published.

The Pentathlon United representatives cited a survey conducted by the group which it says showed that more than 95 per cent of respondents "are unhappy with the way that the UIPM has conducted the change" and more than 93 per cent "are unhappy with the direction the sport is going in".

In the letter, they argue "it is imperative that you publish the results and analysed scores from the more than 60 sprots submitted to the 5th Discipline WG [Working Group]".

In particular, they insist that "the scores of each sport" against a list of 13 criteria published by the UIPM should be made available, as well as against criteria laid out by the International Olympic Committee (IOC).

Criteria set by the UIPM included not being governed by another International Federation recognised by the IOC, tying in with its new 90-minute elimination format set to feature at the 2024 Olympic Games in Paris, being "attractive and relevant for global youth and future generations" and providing "for gender equality and fairness".

"The methodology used to calculate the scores" and "the evidence of athlete support for each sport considered" are also demanded in the letter.

"We would also like to know how each of the 60 considered sports was benchmarked against equestrian and the potential reforms proposed for the show-jumping discipline," the letter adds.

"Finally, we would like to request two accreditations for Pentathlon United at the planned UIPM Test Events in Turkey after the World Cup Final" scheduled for June 22 to 26."

Pentathlon United has been fiercely critical of the process to replace riding since it emerged that it would be dropped from modern pentathlon after Paris 2024, following Germany's coach Kim Raisner being sent home in disgrace for punching a horse in the women's competition at Tokyo 2020.

A Fifth Discipline Working Group, headed by Schormann, was formed to oversee the process, and the UIPM claimed that it considered 61 proposals to replace riding.

A lack of transparency has been among the main criticisms aimed at the UIPM, and Allenby told insidethegames that non-disclosure agreements (NDAs) believed to be signed by participants in the Working Group should not have featured as part of the process.

"NDAs should not have a place in a conversation about a sport to bring into the Olympics in the interests of transparency," she said.

Modern pentathlon has been left off the initial Olympic programme for Los Angeles 2028, and IOC President Thomas Bach has warned that the proposal for riding's replacement and the overall competition format must be finalised before it can be included.