Catherine Walker

A senior member of the Conservative Party, with a formidable reputation, Catherine is chosen to challenge Ros on a special edition of Newsnight. However, she dramatically joins the Purple Alliance moments before her scheduled appearance. A hardline right-winger, Catherine provides political backbone and, with Hilary Rees Benson, does the serious business of politics.

Janet McTeer
An acclaimed actor on TV, film, stage and radio, Janet McTeer won a Golden Globe award and was nominated for both an Independent Spirit Award and an Oscar for her performance in Tumbleweeds (1999), her first major role in an American film.

On British TV she is well-known for her role as Helen Hewitt in Lynda La Plante's prison drama, The Governor. Other television credits have included Portrait of a Marriage, in which she portrayed Vita Sackville-West, Miss Marple: The Murder at the Vicarage, and Five Days, with Hugh Bonneville and Patrick Malahide.

Film credits include Terry Gilliam's Tideland (2005); Wuthering Heights, with Ralph Fiennes and Juliette Binoche, in 1992; and Kenneth Branagh's As You Like It (2006) with Bryce Dallas Howard, Kevin Kline and Romola Garai.