Speaking to SFX, he said said that bringing back ‘The Master’ was an exception: “Even people who don’t know the past very well get thrilled by the idea that you’ve brought something back. Everyone got very excited – and by everyone I mean real people – when the Master came back, even though most people could barely remember him.
“It has to be self-explanatory, it has to be free-standing, it has to be clear for everybody. If I did the Meddling Monk teaming up with Mavic Chen’s daughter and the Krotons then yeah, that’s too much, because no one gives a toss.
He added: “People always ask me “Do you want to bring back the Rani?” No one knows who the Rani is. They all know who the Master is, they know Daleks, they probably know who Davros is, but they don’t know who the Rani is, so there’s no point in bringing her back. If there’s a line it’s probably somewhere there.””