The scripts for the eighth and final season of Game of Thrones have been written and HBO has hinted that some may run to up to 2 hours in duration.

Game of Thrones is currently airing its penultimate season, which consists of seven episodes instead of the usual 10, while season eight will only feature six episodes.

The current season's finale will be feature length and it is possible that trend will continue until the show's last ever episode.

"We haven't had that discussion yet because I don't know how long the episodes are going to be," HBO programming president Casey Bloys told The Hollywood Reporter.

"Two hours per episode seems like it would be excessive, but it's a great show, so who knows?"

With the scripts for the remaining episodes of Game of Thrones completed, attention is turning towards the numerous spin-offs that are being explored by HBO.

While the appetite for more stories from Westeros is there, Bloys said they won't air a spin-off until at least a year after Game of Thrones concludes.

Kit Harington as Jon Snow

"The number one priority in all of this is the final season of Game of Thrones. I don't want to do anything with a spin-off or anything that detracts or distracts from that," he said.

"That season will happen, and my guess is it would be at least a year before you saw anything else. What I don't want is the attention to be drawn from the final season, which I think is going to be epic and amazing, and somehow have the distraction from a new Game of Thrones airing right after that. It's best to separate it, and that's what we'll do."

Game of Thrones season seven continues on Sky Atlantic, Mondays at 2am and 9pm.