George RR Martin says GoT season eight wasn't "completely faithful"

Speaking to Fast Company, Martin said that adapting from book to screen can be "traumatic" due to creative differences, and suggested that the show would have needed a longer runtime in order to tell the full story.

"The [final] series has been... not completely faithful," he said. "Otherwise, it would have to run another five seasons."

Martin also hinted that he and show-runners David Benioff and D. B. Weiss clashed on certain issues, and that the network urged the writers to give certain characters more screen time in order to keep viewers happy.

"Sometimes their creative vision and your creative vision don't match, and you get the famous creative differences thing – that leads to a lot of conflict," he said.

"You get totally extraneous things like the studio or the network weighing in, and they have some particular thing that has nothing to do with story, but relates to 'Well this character has a very high Q Rating so let's give him a lot more stuff to do'."

Season eight scored massive ratings for HBO, but was met with criticism from fans, 1.3m of whom signed a petition demanding that the season be re-done, calling the show's writers “woefully incompetent when they have no source material.” Many were particularly upset that Daenerys Targaryen's (Emilia Clarke) six episode arc, in which she went from revolutionary leader to Mad Queen, felt rushed.

Martin is currently writing the final two books. Volume six, The Winds of Winter, is expected to be released in 2020.