Creator Kris Mrksa has based the series on the first-hand experiences of a witness protection officer who served in the Met for 30 years; a job that is "darker, murkier and far more complex" than most of us realise, teases the synopsis.

Many protected people are themselves criminals, which means officers often have to morally compromise, and they have to actively distrust their own colleagues to maintain maximum secrecy.

Protection is a twisty tale about what happens when that system breaks down. Finneran will play the Detective Inspector, Liz Nyles, who finds herself compromised by an affair with a colleague.

Liz is a smart and tough cop, determined to redeem herself, her lover and keep her witnesses safe. But as she is led deeper into a criminal underbelly, she becomes torn between her loyalties to her family, her lover and the police.

Nadine Marshall (Sherwood) and Katherine Kelly (The Long Shadow) will also star in the series, while Barry Ward (Bad Sisters), Chaneil Kular (Sex Education), David Hayman (Sid and Nancy), Nichola Burley (The Gold) and Akiya Henry (Silent Witness) will play supporting roles.

Mrksa commented: "Protection is a suspenseful conspiracy thriller, but it also explores some complex moral questions, about how far we should be prepared to go in order to serve the greater good.

"The murky world of witness protection, where hardened criminals are often sheltered, in the hope that they will help bring down other criminals, provides the perfect context for examining these thorny issues."

Filming for Protection has begun in Liverpool and it will air on ITV and ITVX in 2024. The series is being produced by New Pictures (Des, The Long Shadow).