After losing a battle to ban the event – planned for June 13 – officials from the western German city of Cologne were holding a crisis meeting with promoters in a bid to limit attendance of the event to adults.

The controversial sport – which former US presidential candidate John McCain once described as “human cock-fighting” – is hoping to build on successful events in Britain and Ireland by staging a 12-bout fight-night in Germany.

According to the website of the Ultimate Fighting Championship (UFC), participants in Cologne will include Wanderlei Silva (“the Axe Murderer”), Ben Saunders (“Killa B”) and Marcus Davis (“The Irish Hand Grenade”).

UFC bouts are staged in an octagonal cage, rather than a ring, and the only rules are that fighter may not gouge each other’s eyes, attack the groin area or bite.

During the five five-minute rounds, attacks continue even when fighters are on the floor with repeated bare-knuckle blows to the head until the referee intervenes or one of the participants throws in the towel.

It is considered the largest mixed martial arts franchise in the world with growing popularity thanks to television.

But Armin Laschet, youth minister from the state of North Rhine-Westphalia, where the event is taking place, dismissed it as a “glorification of violence.”

“Youth protection agencies, schools and local authorities are doing everything they can to fight against glorifying violence and here people are making money out of violence,” Laschet said in an interview with daily Frankfurter Allgemeine Zeitung.

The issue of glorifying violence is especially sensitive in Germany, where politicians are drawing up tighter gun control laws in the wake of a bloodbath in March when 17-year-old Tim Kretschmer shot 15 people and then himself.

There have also been calls to ban violent video games played frequently by Kretschmer.

But UFC supporters say that rather than glorifying violence, the sport is a highly skilful blend of martial arts, including karate, sumo wrestling, taekwondo, judo and jiu-jitsu.

“Supervisors who up until now have not come across UFC will see that our fighters are exemplary and intelligent athletes,” Dana White, the body’s president, said in a statement, adding that in 16 years and over 1,000 bouts, the worst injury has been a broken arm.

Despite the criticism over the event, Cologne officials say they are powerless to prevent its staging in the 20,000-seat stadium.

“I am convinced that the event can not be legally forbidden,” Cologne’s Mayor Manfred Wolf told daily Bild.

The event does not affect the safety or security of the town and therefore no permit is required.