Secret Service writer Tom Bradby reveals real-life basis for his ITV spy drama – and how recent events changed the scripts

New ITV spy thriller Secret Service follows Gemma Arterton's Kate as she investigates evidence which potentially points to a top flight member of the UK government being a Russian asset.

It may seem like a far fetched proposition, but it comes from ITV newsreader Tom Bradby, who has adapted the series alongside Jemma Kennedy from his own 2020 book of the same name.

Speaking at a Q&A for the series Bradby explained the real life events which have inspired the story, saying: "When I first came up with this idea, it was clear to me we're in a new Cold War. It was clear to me that democratic societies were being undermined. There was the question about whether Western politicians were being bribed, blackmailed, corrupted.

"And I just thought, ‘Well, imagine if you were the MI6 officer who actually got the kind of nuclear bombshell intelligence? What would that really be like? How would your bosses react? How would the politicians react?’ And that was where the idea of Kate came from."

Arterton continued: "Originally, I thought about it as a TV series, and I started talking to a couple of people. And then the idea was so clear in my head that I just wanted to get it down as a novel, so I wrote it very quickly as a novel, and then Gail [Egan, executive producer] and I started talking about developing it as a TV series.

"And of course, the world has moved on since I had that idea but, honestly, it just seems to get more and more relevant, which is great for the drama, but possibly not for democratic societies.

"I think what we wanted to do here was to create something that felt like really cracking, suspenseful mainstream entertainment, that was gripping, and obviously all of you will determine whether we succeeded in that, but that also felt really emotional. And finally, that left people thinking a bit at the end. That's not necessarily the purpose of it, but I really hope that may be the result of it."

Bradby explained that while a lot of what he had written in the novel remained relevant, he did have to update elements of the story to meet the current moment.

"The truth about turning anything from a novel into a film, and obviously lots of novelists don't like to do that themselves, but I love doing it, is that I really love the collaborative process, and we had a brilliant team," he said.

"And obviously, it's a new journey. You've had your say in the novel, and then you're going on a journey with everyone else together, and it evolves. And obviously it did have to evolve, because the world was evolving. But as I said, the slightly scary thing is it never felt any less relevant, and still doesn't today, in fact, more so probably."

Alongside Arterton, the series also stars Rafe Spall, Mark Stanley, Alex Kingston, Roger Allam, Amaka Okafor and Khalid Abdalla.

Secret Service starts Monday 27 April at 9pm on ITV1 and ITVX.

Add Secret Service to your watchlist on the Radio Times: What to Watch app – download now for daily TV recommendations, features and more.

Check out more of our Drama coverage or visit our TV Guide and Streaming Guide to find out what's on. For more TV recommendations and reviews, listen to The Radio Times Podcast.