The charity wants flat-faced breeds to be barred from competing.

The RSPCA is calling on The Kennel Club to stop allowing pugs, British bulldogs and French bulldogs to compete at Crufts.

In an open letter to The Kennel Club, the RSPCA has expressed its concern that allowing brachycephalic breeds to compete at Crufts normalises their unhealthy features and promotes their popularity.

The letter forms part of the charity’s Save Our Breath campaign, which highlights the serious health problems experienced by flat-faced dogs owing to selective breeding for extreme features.

Despite breeds such as French bulldogs remaining popular with dog owners, new research by the charity has revealed growing concern among the public about the welfare of brachycephalic dogs.

A survey conducted by Savanta on behalf of the RSPCA found that a majority of respondents (58 per cent) believed that breeds such as pugs and British and French bulldogs should not be allowed to compete at Crufts.

RSPCA dog welfare expert Dr Samantha Gaines said: “It saddens us that each year, large numbers of flat-faced dogs such as French bulldogs and pugs qualify for the competition despite the selection for their extreme features posing risk of serious health and welfare issues.

“Last year, despite less exaggerated versions presented in other classes in the competition, we still saw a more exaggerated bulldog coming first place in the best of breed - so judges thought he was the ‘best’ example of his breed, but at what cost to his health?

“Every year Crufts awards these types of dogs with certificates for best of breed with the potential for one to be named best in show. While some changes have been made to the breed standards, it is far from sufficient and there remains an urgent need to protect these dogs.

“The Kennel Club has the power to inform real change, and has an incredible influence. They get to decide what a Crufts ‘winner’ looks like, and by taking a stand against brachycephaly - and ending the involvement of French bulldogs, British bulldogs and pugs from competitions until these breeds are returned to health - they can help protect future generations of these dogs.”

The charity is inviting members of the public who support their campaign to sign the open letter to The Kennel Club.