The show, which is David Hare's first original screenplay for 20 years, will feature actors including Bill Nighy, Rachel Weisz, Judy Davis, Michael Gambon and Ralph Fiennes.
The drama follows Nighy's character Johnny, a long-serving MI5 officer who is shocked when his boss and best friend Benedict (Gambon) dies suddenly, leaving him a mysterious file.
Meanwhile, Johnny has a seemingly chance encounter with his next-door neighbour Nancy (Weisz), a political activist. Eventually he ends up walking out of his job and "out of his identity" to find out the truth.
The cast also includes Ewen Bremner, Felicity Jones, Tom Hughes, Alice Krige and Saskia Reeves.
Hare said: "The last decade has been as testing as any in the history of the British intelligence community - the compromises and dilemmas they've faced in the new century make a fascinating story. I'm thrilled to be working with such an extraordinary ensemble of great actors."
Filming for Page Eight will begin this month and the film will air later this year.