David Tennant and Billie Piper

 New Doctor Who star David Tennant said it was "pretty daunting" to play the sci-fi character, as filming of new episodes began in Cardiff.

 Ex-Casanova star Tennant, 34, said it was an intimidating role because "The series is so huge. I'm aware of all that but I try to keep it in my back pocket and just get on with the job".

 Last week The Doctor's "striking" new outfit was revealed, consisting of a striped suit, trenchcoat and trainers.

 Billie Piper returns as companion Rose, with a cameo appearance by Buffy the Vampire Slayer star Anthony Head. Also due to return will be the Cybermen, and The Doctor and Rose are also due to meet Queen Victoria and an evil race of Cat Women.

Sarah Jane Smith

It has also been announced that Third Doctor and Fourth Doctor companion Sarah Jane Smith, played by actress Elisabeth Sladen, will be making a return to the series to join David Tennant and Billie Piper for this second series.

Also confirmed Camille Coduri will return as Rose Tyler's mum Jackie and Noel Clarke as her boyfriend Mickey.

 A 13-part series of the BBC TV show will follow a Christmas Special, with scenes shot in London last week. The 60-minute Christmas Special is due to cover the Earth being under threat from alien Sycorax and features actress Penelope Wilton returning to her role as Harriet Jones.

The Christmas Special is due to be screened later this year and season two is scheduled for spring 2006. Writers announced include Russell T Davies, Steven Moffat, The League of Gentleman star Mark Gattis, Toby Whithouse, Tom Macrae, Matt Jones and comedian Stephen Fry. The directors announced include James Hawes, Euros Lyn and Graeme Harper.