Jane Horrocks
as Prime Minister Rosamund 'Ros' Jane Pritchard
Carey Mulligan
as Emily Pritchard
Steven Mackintosh
as Ian Pritchard
Jodhi May
as Miranda Lennox
Janet McTeer
as Catherine Walker
Jemma McKenzie-Brown
as Georgina Pritchard
Geraldine James
as Hilary Rees-Benson
Selina Cadell
as Dorothy Crowther