Labour's choice wins a pat from Anthony Thornton
It was the pepper that did it. The bull, incensed at its treatment and its tethering, would be further enraged by filling his eyes and nostrils with pepper by the laughing villagers. Only then, when the beast was aroused to its most murderous would 50lb dog be loosed upon it.

The bulldog is back in the news following the appropriation of this former bull-baiter and most potent of symbols of Britain by the Labour Party for a party political broadcast.

With an ancestry that can be traced variously back to Roman legionnaires arriving in 55BC with their fighting dogs and to the Molussus fighting dog named after the ancient Greek Molossi tribe, what is certain is that they were surly and unsociable but possessed indomitable courage.

With a dash of mastiff blood to increase its ferocity, for centuries the bulldog was carefully bred to acquire and perfect all the physical attributes that the barbaric "sport" of bull-baiting required. The underhang of the lower jaw enabled it to cling to the bull's muzzle with such tenacity that even the most insane bull found him impossible to shake off. The light, flexible hindquarters permitted the dog to survive as the bull attempted to break its back. The protruding lower jaw and short muzzles let it breathe as it seized the bull's nose and the deep furrows around the eyes allowed the bull's blood to run off the face. Loose skin on the body protected its internal organs.

Endorsement for the breed came from the poet Lord Byron who described his own bulldog, Boatswain, as possessing "Beauty without Vanity, Strength without Insolence, Courage without Ferocity, and all the Virtues of man without his Vices".

Then, in 1835, the "sport" of bull-baiting was made illegal and the bulldog faced extinction. Credit for saving the bulldog must go to a Bill George, who continued to breed them. In 1875 the first specialist club devoted to the breed was established: the Bulldog Club Incorporated.

Such was the reputation of the stocky, courageous dog that his name and mythical temperament came to immortalise the spirit of the people of Great Britain: The Bulldog Breed. The phrase comes from a music hall song by Arthur Reece popular in late Victorian and Edwardian Britain called "Sons of the Sea, All British Born". In turn it inspired the name of Bulldog Drummond, the hero of the adventure novels of Sapper. In them Bulldog Drummond, a former army officer and amateur detective, righted wrongs with resourcefulness and fortitude.

Churchill, in a remark that confirmed the ancient notion that pets look like their owners, declared the bulldog his favourite pet.

Yet ironically, while its reputation as a bold and tenacious animal grew those characteristics were slipping away through generations of selective breeding. The bulldog came to differ from its ancestor and its image in both appearance and disposition. With its deeply furrowed face, wide-set eyes and protruding lower jaw, to the uninitiated, the bulldog appears to be both ferocious and volatile. In reality, however, it is a docile, good-natured and home-loving animal fond of children. And hopeless as a watchdog.

Bulls may sleep easier at night, but there has been complaints that breeding is making the bulldog suffer. The size of its head means that puppies frequently have to be born by Caesarean section. There has been a marked increase in bitches successfully self-whelping but the dog still has a notoriously short life-span. Some say it has been bred to an abnormal size that often interferes with breathing and heart action. Leslie Thorpe, secretary of the British Bulldog Club, disagrees. "I've bred bulldogs for 45 years and their heart problems and breathing problems are no worse than any other breed as long as they get exercise and eat healthily," he says.

Is he happy with Labour's appropriation of the bulldog as its election symbol, an idea used by the Conservatives in 1987? "Well, it's always been a symbol of the Conservatives and, put it this, way I wouldn't let them use any of my bulldogs."

Susan Jay, secretary of the London Bulldog Society, is more equivocal about the use of Fitz the bulldog in politics. "It's part of the burden of being a bulldog, I suppose," she says. "It always gets trotted out at every opportunity. But it is a very clever advert."

There is a dark side to the bulldog spirit, which should worry those who see a real bulldog breaking its leash as shown on the Labour broadcast. Some unscrupulous breeders are attracted to the possibility of breeding the bulldog with a view to re-activating the ferocious temperament dormant in its genes for more than a century.

However docile the beast there is an important lesson to be learnt from bulldogs, which Tony Blair may find relevant in his future struggles with old Labour should he lead the next government: as they become older crankiness and irritability are common. Theybecome increasingly over-anxious and bark frequently.