Steven Moffat has spoken about the "tremendous pressure" of writing Amy and Rory Pond's exit from the series, and the demands of introducing a new companion to the show.
“The event status of Amy and Rory leaving, which I've just written --
you feel tremendous pressure with that because you don't know if you've
enjoyed a story until it's over, and this is the ending", the Doctor Who executive producer told the Huffington Post.
He added: "And then bringing someone else in [new companion Jenna-Louise Coleman, who debuts next season]. All that is massively demanding.”
Moffat also admitted he finds it “tough to keep going” while marketing the BBC sci-fi show because of the number of episodes produced compared to his other TV hit Sherlock.
"Doctor Who seems like it was always there, always turning out more episodes. It's harder to up the game when people get almost decadent about how much we give them.
"Yes, we've got big exciting things coming and we're always trying to work out how to get Episode 7 coverage in the newspapers. Obviously Episode 1 will [be written about], but how do you make that one a must-see?
"There's a constant game of that, because "Doctor Who" is an expensive show, it has to be very near the top all the time."
The new series of Doctor Who will be broadcast on BBC1 in the autumn.