A “major studio” behind an animated television series is requiring child actors to surrender their voices to use by generative AI in their contracts, according to a group of agents who specialize in working with minors.

The U.K.-based Agents of Young Performers Association made the allegations in an open letter to the industry published on Monday. Deadline has reported that the series in question is Peppa Pig, which airs on Nick Jr. in the U.S.

“Most recently, a major studio who owns the IP for an international children’s franchise producing a long running animated television series has offered contracts to child voice actors insisting that they agree to the use of AI thus allowing them to use the child’s voice in all commercial assets within their franchise,” the letter, which has more than 1,000 signatures from representatives and actors, stated. “The refusal to remove this clause with an attitude of ‘take it or leave it’ has led us write this letter to make it clear that this will not be accepted and to bring this matter to the attention of the wider industry.”

In a statement Hasbro, which owns the brand, did not deny that the series in question was Peppa Pig. “Hasbro is aware of the open letter circulating regarding AI clauses in children’s performance contracts. We are not able to comment on specific negotiations or contractual arrangements,” the company stated. “The protection of child performers is core to who Hasbro is; it’s part of our DNA. As industry standards around AI continue to evolve, we are committed to engaging with this issue in a responsible and transparent manner.”

The AYPA’s position is that any contract for a child actor should exclude AI use altogether. “Children cannot provide fully informed legal consent and a parent or guardian’s approval should never be used as a blanket licence to capture, clone, train, or reuse a child’s voice indefinitely,” the letter continued. The group argues that AI use of a child’s voice could determine their professional futures before they can legally consent to such a practice or totally understand the potential repercussions.

“We the undersigned urge you to commit to responsible industry practice,” concluded the letter. “Collectively, we reject all contracts that require child performers to surrender voice rights indefinitely and without limits.”

The board of the AYPA says the issue is larger, however, than one television series. In the U.K., performers cannot join the actors’ union Equity until they are 10 years old and child actors’ parents are being asked to sign contract language regarding the use of generative AI. “Our letter addresses the universal issue of companies supporting the use of AI in contracts for minors,” the board said in an email to The Hollywood Reporter.