King Charles’ official portrait attacked by animal-rights protesters in London M Haris

The painting itself was unharmed, said the Philip Mould Gallery, and there were no arrests. The striking red artwork by Jonathan Yeo, unveiled last month, was the first official painting of the King since his coronation.

The Animal Rising group said its supporters had stuck posters to the glass protecting the painting, in what they described as a “light-hearted” action. They pasted over the royal portrait with a picture of Wallace, a character from the Wallace and Gromit animations.

It was a protest message criticising the welfare standards of RSPCA “assured farm” status, with King Charles a patron of the RSPCA. “With King Charles being such a big fan of Wallace and Gromit, we couldn’t think of a better way to draw his attention,” said Daniel Juniper of the campaign group.

The gallery, which has been showing the painting to the public for free, said the incident was over quickly and no harm had been done to the artwork. The Metropolitan Police said they had not been called, but in response to footage on social media, officers had visited the gallery to make inquiries.

“Staff at the venue were spoken to. They confirmed no damage had been done to either the painting or the glass that covered it,” said a Met statement. “The protestors were asked by staff to leave following the incident, which they did.”

The gallery did not wish to report a crime and as such there is no further action by police.