Prominent writers say free speech is under threat after a British court halted publication of a celebrity's memoir of child abuse because his ex-wife argued that it would harm their son.

Three appeals court judges last week temporarily stopped publication of the book, which has already been printed and was due to be published this fall.

They described the author as a "talented young performing artist" whose ex-wife lives abroad with their son.

She argued the book would cause "psychological harm" to the boy, who has Asperger's syndrome and other disabilities.

The judges granted an injunction stopping publication of key sections of the book pending a full trial.

On Friday writers including Tom Stoppard, David Hare and Stephen Fry called the ruling "a significant threat to freedom of expression."