When I really felt in the firing line... at the premiere of my first film

Tom Bradby has been shot during riots in Indonesia, he has reported from Northern Ireland at the height of the troubles, and he has unwittingly triggered the biggest crisis in the British media for a generation. But the ITV News Political Editor has found a new terror – attending film premieres as a guest of honour.

Walking into the prestigious Sundance Film Festival in Utah last month, Bradby was gripped with fear as he anticipated his debut feature film being shown to an audience for the first time. Shadow Dancer, a film starring Clive Owen and Andrea Riseborough based on a screenplay Bradby had developed from his own 1998 novel of the same name, had been completed only two days earlier and he was suddenly overcome with self-doubt.

"You walk into this theatre full of 1,200 people – critics, sales agents, filmgoers – and I was just absolutely terrified," he says. "Because it's a story I idly thought up walking down the Falls Road [in Belfast] one day and everything – the story, the dialogue, everything – came out of my own head. You think 'What if they hate it?'" The film has since had a slew of favourable reviews.

It's not as if Bradby, 45, has never put himself in the firing line before. His 22 years at ITV News have taken him to conflict zones from Ulster to East Timor, and he has taken on the challenges of covering the royal beat – where he became friends with Princes William and Harry – and the cauldron of Westminster. From tonight he will add something new to his workload by presenting a weekly topical talk show, The Agenda.

Bradby is continuing his film-writing with an adaptation of Defence of the Realm, the 1985 Cold War political thriller starring Gabriel Byrne. "I initially said no but then I came up with a really interesting angle – to effectively replace the Cold War with the War on Terror and [look at] what the state might do in defence of the realm there. I think it's much more nuanced because the truth is that the public would probably support much stronger action in that regard than they would in the Cold War."

He has enjoyed the project because of its topicality. "It's quite pertinent because it's about a tabloid journalist who rediscovers his journalistic soul. And it's about the media and the politicians and whether they are too close." These are areas the Political Editor knows well, especially as it was his offer to loan some editing equipment to Prince William which helped to uncover the phone-hacking scandal when details taken from their voicemails appeared in the News of the World. "It just happened to be me that set the first pebble going that took a few rocks that ended up taking half the mountain and eventually the entire valley."

With the Sunday edition of The Sun having restored a little of that valley, Bradby is intrigued as to what the new publication means for Westminster. "Put bluntly: are people going to regret being so rude about Rupert Murdoch? At the end of this process there's a reasonable chance he is still going to own an awful lot of very influential British newspapers."

Bradby argues that the relationship between Mr Murdoch's News International and government had "got really bizarre" and that the Leveson Inquiry process will help to reintroduce a healthy distance between politicians and the media.

He became aware of strange tabloid tactics when he gave up foreign reporting and took the post of ITV Royal Correspondent over a decade ago. "They had almost mystical powers," he says. "It started in the Diana and Charles years. That was the biggest commercial newspaper story on the planet and more or less anything went. Nobody has ever adequately explained how the hell Squidgygate got [out] – or the other [intercepted call] between Charles and Camilla – don't tell me that was some radio ham. Oh yeah, right!"

The Agenda will be filmed "as live" at the Hospital Club in Covent Garden, London, and shown at 10.35pm, after News at Ten. The programme, which of course was Bradby's own idea, will feature four studio guests. He says it will be different from the BBC's Question Time due to its start-of-the-week slot and because the presence of only one politician (tonight's will be Boris Johnson) will mean "a bit less tribalism than you get elsewhere".

Some nights Bradby will report on the bulletin and host his show afterwards. There's no danger of him being afforded celebrity status. "People are not at all intimidated when they see you. They think that's the guy off the news and immediately start a conversation," he says, describing how a builder climbed off a scaffold at 7am to engage him in political discussion as he walked along a street. "Being a TV reporter ... people have this familiarity and feel they can chat with you. It's really attractive and I've never found it anything other than quite charming."