Peta wants to highlight the condition of sows in restrictive cages
Animal rights activists have targeted chef Jamie Oliver's north London restaurant to protest against his endorsement of British pork.
People for the Ethical Treatment of Animals (Peta) activists highlight the condition of sows who are kept in cages for a month after the birth of piglets.
Two naked heavily pregnant campaigners have placed themselves in cages outside Fifteen in Islington.
Oliver's spokesman said the chef was a "big supporter" of animal welfare.
In a recent programme on Channel 4, Jamie Saves Our Bacon, the chef showed the conditions in European pig farms where sows are kept for about four months in individual cages through pregnancy.
'Unhappy Mother's Day'
He urged people to buy British pork saying that conditions for pig rearing are more humane in the UK.
But Peta said: "The answer to saving pigs is not to buy British pork, it's to go vegetarian."
The pregnant activists protested holding a banner reading "Unhappy Mother's Day for British pigs", and asked people to "avoid meat that comes from such misery".
Peta wants British pig farms to stop using the restrictive cages where they say sows spend one month out of every five before they are killed.
The spokesman for the chef said: "They do seem to be protesting against somebody who is trying to help the situation.
"In the programme we never said that the British pig farming industry is completely whiter than white, we did a very balanced programme."