Simon Pegg's Channel 4 cyber-thriller "The Undeclared War" is being lined up for a third series, following supportive comments from Pegg and co-star Hannah Khalique-Brown. The show, which pairs a grounded espionage story with Pegg's established fame from the Cornetto Trilogy and the Mission: Impossible franchise, has been praised by critics but has struggled to gain wide attention despite favourable comparisons to series such as 24 and Homeland.

The first season aired in 2022 to strong reviews, with Peter Kosminsky directing every episode, but a four-year gap followed before season two arrived with new cast additions Ed Stoppard and Chloe Pirrie. Speaking to Radio Times, Pegg said he would "absolutely" return and had already discussed possible directions with the writer, while Khalique-Brown said the "scope is there" for further storylines, though she cautioned it remains uncertain whether a third season will actually happen. Pegg also contrasted the show's realism with his fantastical Mission: Impossible role, noting that its depicted technology is grounded in reality.