David Tennant admits he's jealous of new Doctor

David Tennant has admitted he is 'jealous' of his replacement on Doctor Who Matt Smith, who is set to hit screens in the role next year.

Speaking at the launch of The Doctor's latest adventure, The Waters Of Mars, which sets the foundations for the beginning of the end of Tennant's incarnation as the Timelord, he said: "I remember how exciting it was starting out on this kind of a journey and nerve-wracking - I'm jealous that he's going through that now, but it couldn't happen to a nicer chap.

"I'm looking forward to not knowing what happens next. I'm looking forward to being a viewer again."

The episode is the second Doctor Who special to be screened this year, and Tennant will also star in two more shows before bowing out in tear-jerking scenes.

Set on Mars in 2059, The Waters of Mars guest-stars acclaimed actress Lindsay Duncan as Adelaide - the Doctor's 'cleverest and most strong-minded companion yet'.

She and the Doctor face terror on the Red Planet in what is being seen as one of his darkest and scariest adventures.

Neighbours, Flying Doctors and Casualty star Peter O'Brien also guest stars as Ed, Adelaide's second-in-command at the base.

Tennant said of the special: "The Doctor finds himself in a situation where he knows what the end is. It's all about whether he can un-knit the inevitable.

"With this particular Time Lord's life coming to an end, if he starts fiddling with the fundamentals of time and space, it might lead to his undoing."

The Waters Of Mars will hit screens on Sunday, November 15 at 7pm on BBC1.