Campaign group Authors United is being "forced to move on to our next initiative" because Amazon has not yet halted its dispute with Hachette Book Group in the US.
The group's founder, Douglas Preston (pictured), also said he hoped Amazon would not "start targeting" Simon & Schuster books, as the publisher has recently entered negotiations with Amazon. Preston was writing to those who signed Authors United's letter to Amazon, which was printed in the New York Times.
The letter, signed by writers including Stephen King, James Patterson and Lee Child, called on Amazon "to resolve its dispute with Hachette without hurting authors and without blocking or otherwise delaying the sale of books to its customers".