Two Just Stop Oil activists have been ordered to pay Madame Tussauds £3,500 compensation after smearing chocolate cakes in the face of waxwork King Charles.
The cakes were topped with shaving foam.
The couple were found guilty at Westminster Magistrates’ Court in Central London of criminal damage.
The King Charles’ effigy needed repainting after the stunt.
His jacket, bowtie, and shirt needed to be dry-cleaned.
The models at Madam Tussauds can cost up the £200,000 to create.
They were removed from display and the museum – one of London’s most popular – was closed during a busy half-term week.
More than an estimated 900 tickets sales were lost during the hour-long closure.
The accused Tom Johnson, 29 said he and Eilidh McFadden, 20, rejected the idea of using hot soup.
He added: The substance was carefully chosen to inflict as little damage as possible.”
McFadden told the court she had practised the cake stunt with another person.
She said: “Shaving foam on a waxwork is nothing compared to the damage we see from the climate crisis.”
Jonathan Bryan, prosecuting, said:
“Your actions have done nothing whatsoever to help those persons effected by climate change, have they?
“Putting a custard pie on a waxwork model of King Charles is not going to convince anyone about climate change, it is a totally trivial action.”
He told the court:
“Mr Johnson and Ms McFadden, like thousands of others, went into and made their way through the room in which models of the royal family were on display – four figures including King Charles, Queen Camilla, Prince William and Princess Kate.
“However, Mr Johnson and Ms McFadden weren’t there simply to enjoy the display and take some photos for their friends, they were climate protesters from Just Stop Oil.
“They removed their outer clothing to reveal Just Stop Oil T-shirts they were wearing underneath.
“They took out a cake, topped with some sort of foam and each in turn slapped the cake into the face of the model of King Charles rather in the manner of a slapstick comedy using custard pies.”
District Judge Neeta Minhas convicted Johnson and McFadden of causing £3,500 of criminal damage.
She said: “If the damage is significant, even within a peaceful protest, it would not be disproportionate to have a conviction and I find you both guilty.”
Self-employed artist Johnson, who has no previous convictions, was given a 12-month conditional discharge.
He was ordered to pay £1,750 compensation and £250 costs.
McFadden, who has three previous convictions for aggravated trespass, was ordered to pay the same amount of compensation and costs.
She was given a 12-month community order, including 80 hours of unpaid work.