Olympic champion Joe Choong will walk away from modern pentathlon if its governing body (UIPM) pushes ahead with a controversial plan to replace horse riding with obstacle racing, the Briton told Reuters .

UIPM has selected two variations of obstacle racing for testing, from more than 60 options, to replace show jumping in time for the 2028 Olympics in Los Angeles.

The decision followed widespread criticism after a German coach struck a horse that refused to jump a fence at last year's Tokyo Games.

Pentathlon United, a group formed to oppose the change, has urged the International Olympic Committee (IOC) to intervene, saying UIPM's consultation process was "illusory at best".

It said an April survey of 310 athletes -- 168 of them active -- showed more than 95 per cent were unhappy with the way the change was being made, while 77 per cent said they would probably leave the sport if equestrianism was removed.

READ: Obstacle course race set to replace equestrian in modern pentathlon

Choong, 26, said he would "100 per cent be stopping" if UIPM went ahead. "By taking horse riding away, it's not the same sport I fell in love with," he added.

UIPM said in a statement that a focus group of 26 athletes from 22 countries was involved in the decision-making process.

Modern pentathlon was introduced by Baron Pierre de Coubertin, the founder of the modern Olympics, at the 1912 Stockholm Games as a representation of the skills required of a cavalry officer -- fencing, swimming, equestrianism, shooting and running.

In the 1990s it was squeezed into a one-day format, while cross-country riding was replaced by show-jumping.

"AFRAID OF CHANGE"

The equestrian aspect has been criticised because athletes cannot ride their own horses, competing instead on those assigned to them. That criticism was among the reasons why UIPM embraced television-friendly obstacle racing, the governing body's vice-president Joel Bouzou told Reuters .

Frenchman Bouzou previously said a 45-minute programme would be ideal for American TV audiences.

"Some of these athletes who are 'fighting' UIPM... don't want to listen that the change is necessary. They want absolutely to stick to the old thing," Bouzou said.

"Maybe because they're good competitors at the moment and afraid of change or maybe because it's a philosophy they have. So they try to find an argument to support their cause.

"The future can be bright if we embrace the change and we're working with top experts on this."

Choong said the UIPM board needed shaking up, adding: "The current leadership, who have been in place for at least 28 years, won't change their opinion. There's a bit of an echo chamber where the president Klaus Schormann has all friends on the board with him.

"When they come up with an idea, one of them will propose something and then the others will just blindly support it."

Choong said the sport was not without flaws, especially with regard to athlete and animal welfare, but that equestrianism had to stay on the programme.

"It's such a vital part," he said. "Without it, we lose the soul of the sport."