David Tennant is to stand down as Doctor Who, after becoming one of the most popular Time Lords in the history of the BBC science fiction show.

Tennant stepped into the Tardis in 2005, and will leave the role after four special episodes are broadcast next year.

He made the announcement after winning the outstanding drama performance prize at the National Television Awards.

"When Doctor Who returns in 2010 it won't be with me," he said.

"Now don't make me cry," he added.

"I love this part, and I love this show so much that if I don't take a deep breath and move on now I never will, and you'll be wheeling me out of the Tardis in my bath chair."

Three years was "about the right time" to play the role, he told the BBC.

"I think it's better to go when there's a chance that people might miss you, rather than to hang around and outstay your welcome," he said.

I don't ever want it to feel like a job, so I want to move on when it still feels exciting and fresh

David Tennant