She said: “When I saw the episode, where Peter’s Doctor regenerates into myself, we were midway through shooting… I hadn’t watched it to try and give myself that freedom to step on set.
“And then when I watch that, I was like, ‘Oh my God, I’ve done it wrong. I’ve done it wrong…’.
“They said, ‘No… you aren’t supposed to be doing what someone else did’.
“But,” Whittaker added, “all the energy of the Doctor and all the references and the Whovian kind of pearls are in there.
“And you then take it and run with it. And actually it’s much more freeing.”
She also told Doctor Who fans that the Christmas special would be “definitely worth the wait”.
Jodie Whittaker: I feared I had it wrong when I first played the Doctor