•
Gemma Arterton as Kate Henderson, an MI6 officer and head of the Russia Desk •
Rafe Spall as Stuart Henderson, Kate's husband and a
special adviser to Conrad •
Alexander Terentyev as Sergei Malinski, an
SVR operative, old friend and informant of Kate, codename "Cyclops" •
Roger Allam as Sir Alan Brabazon, the
Chief of MI6, codename "C" •
Avi Nash as Ravindra "Rav" Sangvhi, an MI6 Russia Desk officer working for Kate •
Mark Stanley as
the Rt Hon Ryan Walker MP, the
Foreign Secretary aligned with the centre-right wing of the
Labour Party •
Alex Kingston as Rose Trewen, the Head of Security for MI6 •
Amaka Okafor as the Rt Hon Imogen Conrad MP, the
Home Secretary aligned with the left wing of the Labour Party •
Khalid Abdalla as Zak Hussein, the Deputy Chief of MI6 and Kate's superior •
Aoife Hinds as Julie Price, an MI6 Russia Desk officer working for Kate •
Rochenda Sandall as Melissa Morris, a special adviser to Walker •
Lydia Leonard as Amanda Walker, an
auctioneer and Ryan's wife • Steven Elder as the Rt Hon Anthony Fletcher MP, the
Prime Minister and
Leader of the Labour Party • Alma Prelec as Lena Savic, an MI6 asset and nanny employed by Mikhail Borodin, codename "Echo" • Galaxie Clear as Fiona Henderson, Kate and Stuart's teenage daughter • Harley Barton as Gus Henderson, Kate and Stuart's son • Juris Zagars as Lev Amatov, a British–Russian oligarch and political donor • Michael Tcherepashenets as Mikhail Borodin, Igor's son and Lena's employer • Petar Zekavica • Miglen Mirtchev as Igor Borodin, the
Director of the SVR •
Ben Lloyd-Hughes as Joshua Long •
Ed Balls as himself (cameo role) •
Susanna Reid as herself (cameo role) == Episodes ==