Vegan campaigners protest outside Yorkshire abattoir

The campaigners, part of the global Save movement, said they wanted to highlight that pigs are no different from pets.

"Why love one but eat the other?" read one of the placards held up by members of the dozen-strong group outside the abattoir at Preston, near Hull.

Campaigner Leon Snowe said they were not targeting Cranswick Country Foods specifically.

But he said the sight of trucks bringing animals to slaughter - they were gassed with carbon dioxide to stun them before being killed, he claimed - was "horrendous..heartbreaking".

He said: "This is to raise awareness, to show people what's happening here.

"It's to show people that these animals are just the same as the animals that are considered as pets. They feel pain, they suffer, they want to live.

"Pigs have the cognitive ability of a three to four-year-old child. They are more intelligent than dogs.

"Just because we have done something for a long time does not make it right."

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Mr Snowe said the switch from meat to plant-based food was "not going to happen overnight (it will be as) more and more people turn away from animal products and demand decreases."

Asked about the jobs that rely on work at the abattoir and in the area in pig farming, he said: "They can make money in other ways - not off the back of innocent animals."

Hull Pig Save's website says their goal is to "to inspire people to choose a more compassionate lifestyle, through transitioning to a vegan diet".

The Save movement started in December 2010 with demonstrations outside a slaughterhouse in Toronto, Canada. There are now over 660 groups worldwide.

Cranswick Country Foods was unavailable for comment.