Sign up to FREE email alerts from Mirror - celebs Subscribe Thank you for subscribing We have more newsletters Show me See our privacy notice Invalid Email

The two men at the centre of Doctor Who's success have now both admitted they are getting tired by the job.

In a new US interview show boss Steven Moffat said making the show is "knackering work" for him while Matt Smith did little to dispel rumours of his exit.

Entertainment Weekly said Moffat admitted that "statistically he is nearer the end than the beginning" of his tenure.

Moffat added: "I just take it a year at a time. I think the feeling of it being done for you is quite unambiguous when it suddenly arrives."

The American magazine had huge feature on Doctor Who which also insisted Jenna Louise Coleman will definitely be on the show in 2014.

But Matt Smith, who the Mirror previously reported could be leaving at Christmas, again refused to commit long term.

He said: "Who knows? It's one of those jobs that I take moment by moment."

Filming of Doctor Who takes up to ten months of the year, leaving little time for other projects. Moffat also writes and makes Sherlock, while Smith has plans to go to Hollywood and also wants to begin a career behind the camera directing TV.

Speaking last September, Smith admitted the show left him tired.

He said: "I couldn’t do this for seven years. I’d be run into the ground. I don’t think you can sustain it.

“And your life outside of it is ... I don’t know. I hope I don’t sound too ­pessimistic.

"It’s just I don’t think my body or my life or the people around me could sustain it.”

The show returns to BBC1 next Saturday, and Smith also said the series had a "great alien-planet episode and a great horror-movie episode".