David Tennant has announced that he is vacating the Tardis and leaving the BBC's Doctor Who series at the end of next year.

Tennant's decision brings to an end his popular four-year tenure as the time lord.

The BBC confirmed that the Scottish actor will complete the filming of four special episodes to be screened this year and in early 2010, as well as 2009's Christmas special.

Tennant broke the news of his departure at the National Television Awards as he accepted the outstanding drama performance prize. He said: "When Doctor Who returns in 2010 it won't be with me. The 2009 shows will be my last playing the doctor.

"If I don't take a deep breath and move on now, I never will."

Speaking about his time on the show, Tennant added: "It has been the most brilliant and life-changing time. But it's not over yet, I have a whole other year to go.

"Thank you for being so enthusiastic about the show, for watching it, and loving it."