A vegan activist invited on the Jeremy Vine Show to speak about the recent complaints by farmers about militant campaigners reportedly harassing them was distracted and infuriated by a ham and cheese sandwich.

Mr Vine had left his lunch on display in the studio as he interviewed Joey 'Carbstrong', an Australian celebrity vegan activist with tens of thousands of social media followers, who is touring the UK in order to spread the word about his plant-based lifestyle.

The 31-year-old former convict, whose real name is Joey Armstrong, stopped in his tracks to criticise the presenter's lunch choice.

He said: "I'm a bit upset to see your sandwich has a piece of a pig's body in there. A dead pig that didn't want to die.

"Ham is a euphemism that actually comes from the flesh of a dead pig."

Mr Vine asked: "What would you rather call it?"

Mr Carbstrong replied: "I'd like you to call it the dead body of an animal that didn't want to die."