Protesters have covered a portrait of the King with the face of the animated character Wallace from Wallace and Gromit.
Animal Rising shared a video of campaigners pasting Wallace’s head over Charles’s and adding a speech bubble on top of the red-hued painting by Jonathan Yeo.
The speech bubble read in capitals: “No cheese, Gromit. Look at all this cruelty on RSPCA farms!”
The portrait is on public display at the Philip Mould Gallery in London.
Animal Rising said two supporters entered the gallery at around midday on Tuesday and plastered two posters on top of the large portrait.
The demonstration was aimed at highlighting the group’s “damning investigation” into 45 RSPCA “assured” farms, the group said.
It added that the protest was a “comic redecoration” and said the posters were affixed using water sprayed on to the back, so they could be easily removed.
It is understood the painting is behind Perspex and so no damage has occurred.
The group said the “light-hearted action played on the King’s love of Wallace and Gromit”.
The Queen once revealed that inventor Wallace and his dog Gromit – the stop-motion animation stars of hit Aardman films including The Wrong Trousers and A Grand Day Out – were her husband’s “favourite people in the world”.
The King is royal patron of the RSPCA, and Animal Rising called on the monarch to suspend his support for the charity.
Daniel Juniper, a former early years practitioner and one of those involved, said: “With King Charles being such a big fan of Wallace and Gromit, we couldn’t think of a better way to draw his attention to the horrific scenes on RSPCA Assured farms.
“Even though we hope this is amusing to His Majesty, we also call on him to seriously reconsider if he wants to be associated with the awful suffering across farms being endorsed by the RSPCA.
“Charles has made it clear he is sensitive to the suffering of animals in UK farms; now is the perfect time for him to step up and call on the RSPCA to drop the Assured Scheme and tell the truth about animal farming.”
The report, released by Animal Rising on Sunday, contains findings from investigations on 45 farms across the UK featuring chickens, pigs, salmon, and trout.
It alleges 280 legal breaches and 94 breaches of Defra (Department of Environment, Food and Rural Affairs) regulations, with Animal Rising calling on the RSPCA to drop the scheme.
Animal Rising describes itself as a non-violent, people-powered organisation working towards a sustainable future where humanity shares a positive relationship with animals and nature.
Animal Rising spokeswoman Orla Coghlan, a former children’s nurse, said: “Just as Feathers McGraw fooled Wallace into a bank heist, the RSPCA has been fooling the British public into thinking their factory farms are – in any way – an acceptable place for animals to live.
“It’s clear from the scenes across 45 RSPCA Assured farms that there’s no kind way to farm animals.”
The RSPCA has been approached for a comment.
Buckingham Palace declined to comment.
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