The two-day event challenges riders from six city districts to encourage their mounts to run along a 100-metre (328-feet) track up a steep hill that includes clearing a difficult two-metre high embankment before they can enter the precincts of the Tado Taisha Shinto shrine.

Horses frequently balk at the obstacle and footage shows onlookers slapping them as they approach the embankment, as well as hitting them with ropes, sticks and whips.

“Following a backlash over the euthanisation of Merzouga, a council made up of shrine officials, representatives of the prefecture, local police and local residents met behind closed doors on June 19 at the shrine,” Yabuki said.

“The council then told local media that the structure of the hill, including the wall, was to be reviewed.”

Yabuki’s group accuses the jockeys, event organisers, shrine officials and functionaries from the six districts that selected the horses for the event of violating animal welfare laws.

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A similar complaint has been filed against the festival’s on-site veterinary surgeon, claiming he failed in his duty to report animal abuse to the prefectural authorities and police.

Yabuki said his complaint was backed by 140 incidents caught on video and that while forcing the horses to mount a dangerously high wall was wrong, that was only one element of animal rights activists’ objections.

He said that the entire environment was dangerous for the horses, and that being surrounded by people who yell at them and subject them to violence was also “extremely stressful” for the animals.

Ensuring the safety of the horses and spectators in such an environment was “impossible”, he said.

“Unless the obvious acts of abuse – beating the horses with sticks, punching and kicking them, hitting them with ropes and yelling – are recognised as violations of the Animal Protection Law, then the fundamental problem behind this ritual will never be resolved,” he said.

“The event has been transformed from a tradition into entertainment and it needs to be ended as soon as possible.”

Critics insist the festival was originally a parade on horseback through city streets by people wearing elaborate costumes who arrived at the shrine to pay homage to the gods and to pray for a good harvest. Only in recent decades – apparently since the end of the 1940s – has the additional obstacle of the embankment been added to make the festival more of a spectacle and to attract more visitors.

In a statement, a city council official said it first began to receive complaints about animal cruelty in 2004 and that the criticism has increased gradually. The official said no animal rights activists protested at the festival but added that it had since “received feedback from many people”.

The shrine issued their own statement that said the well-being of the horses had been discussed in advance with the city government and animal welfare organisations.

It added that those involved had “strived” to comply with laws, and that there had been a “lot of misinformation” about the injuries sustained by the horses.

Yabuki said the organisers’ claims were inadequate and that legal action was the only way to protect the horses expected to take part in next year’s festival.