Franklin as Mike Travis MP, Minister of State for Counter-Terrorism, who grows increasingly resentful over being excluded from Montague's dealings with MI5. Nicholas Gleaves as The Rt. Hon. Roger Penhaligon MP, the Government Chief Whip, Member of Parliament for Surrey North and Montague's ex-husband. A staunch supporter of the Prime Minister, he becomes increasingly suspicious and wary of Julia's political ambition. David Westhead as The Rt. Hon. John Vosler MP, the Prime Minister and Leader of the Conservative Party. Paul Ready as Rob MacDonald, Special Advisor to the Home Secretary, who has a crush on Montague. Police Gina McKee as Commander Anne Sampson, Head of Counter Terrorism Command (SO15) and Sharma's superior. Threatened by Montague's preference for MI5, Sampson enlists Budd's help. Pippa Haywood as CSI Lorraine Craddock, Budd's commanding officer at Protection Command who assigns him to protect Montague. Ash Tandon as DCI Deepak Sharma, a senior detective in SO15 leading the investigation into the recent series of terror activities. As things fail to add up, he becomes suspicious of Budd. Nina Toussaint-White as DS Louise Rayburn, an SO15 officer working under Sharma who starts to work with Budd. Security Service / MI5 Stuart Bowman as Stephen Hunter-Dunn, Director General of the Security Service (MI5), whose surveillance powers will be significantly enhanced by RIPA 18. Montague's preference for MI5 over SO15 puts him at odds with Sampson. Michael Shaeffer as "Richard Longcross", an enigmatic MI5 agent working under Hunter-Dunn who becomes involved in a cat-and-mouse game with Budd. Criminals Tom Brooke as Andy Apsted, a war veteran and friend of Budd's. Scarred both physically and mentally by his experiences in Afghanistan, Apsted leads the anti-war Veterans Peace Group and attempts to kill Montague. Matt Stokoe as Luke Aikens, a mysterious organised crime leader. Anjli Mohindra as Nadia Ali, implicated with her husband in an attempted bombing. Recurring Family Matthew Stagg as Charlie Budd, David and Vicky's 8-year-old son. Bella Padden as Ella Budd, David and Vicky's 10-year-old daughter. Government Shubham Saraf as Tahir Mahmood, Montague's PR Adviser. Stephanie Hyam as Chanel Dyson, the PR Advisor to the Home Secretary before getting fired by Montague. Police Claire-Louise Cordwell as Constable Kim Knowles, a Protection Command bodyguard in Budd's team. Richard Riddell as Constable Tom Fenton, a Protection Command bodyguard in Budd's team. Episodes Production The series was largely filmed on location in London, including the Whittington Estate for Budd's flat