Crufts is under pressure to break with tradition and allow “Retro Pugs” with un-squashed faces to compete in their famous showring, as campaigners say it would help end the “extreme suffering” of purebred dogs.

Pugs can struggle to breath due to their flat faces and narrow nostrils, and campaigners say that Retro Pugs, which are a mix between Jack Russell Terriers and Pugs and have longer faces, are a less cruel alternative.

In the late nineteenth century, all pugs looked like the Retro Pug and campaigners say the squashed face now considered a defining feature of the breed is the result of aggressive breeding.

Crufts, now in its 128th year, traditionally only permits pure breeds to compete in their infamous showring. But Jemima Harrison, founder of the Campaign for the Responsible use of Flat-Faced Animals (Cruffa), said the new Retro Pug is a “big improvement” on the regular breed and that The Kennel Club, who organise Crufts, need to do more to help eradicate the complex health issues the dogs face.

“Of course Retro Pugs should be allowed to compete,” Ms Harrison said. “If the Kennel Club truly want to be seen as a modern organisation that supports animal welfare then they should be encouraging efforts to breed these healthier dogs by allowing them to show.