“I think if radio was invented by Bill Gates tomorrow it would be the greatest invention ever made,” LBC’s Nick Ferrari tells Press Gazette while clutching his Journalist of the Year award.

“Because you can do anything… while you are listening to the radio. It’s the complete complementary medium, which is what I think makes it so potent.”

Ferrari also picked up the popular journalism prize at the Press Gazette British Journalism Awards for public interest journalism – partly in recognition of his pre-election interview with shadow home secretary Diane Abbott.

According to the awards judges, this created the “where were you” moment of this year’s general election campaign.

In the interview with Ferrari on 2 May, Abbott struggled to say how much a Labour Party policy to recruit an extra 10,000 more police officers would cost. At one point the Hackney North MP claimed it would be £300,000 – equivalent to £30 per police officer.

Shortly before the general election on 8 June, Abbot faced another tough interview on Sky News and then unexpectedly pulled out of two planned media appearances “due to illness”. She later revealed she had type two diabetes and that it had gotten “out of control” during the campaign.

Given his interview had seemingly been the start of Abbott’s difficult patch – in which she temporarily was removed from the Shadow Cabinet prior to polling day – did Ferrari regret his part in it?

“If it is your day, it’s a general election, it is the Shadow Home Secretary’s day, you’re going to be talking about how you’ll revolutionise the police, I don’t think it’s asking that much to try and make your figures stack up,” he told Press Gazette.

“If she was suffering some kind of illness then of course, [I have] nothing but sympathy towards her, but as it was presented she was fairly robust in interviews before me so, if she’s ill I wish her well and I’m grateful for this extraordinary night, but I think she did actually bring what she thought was her A game and it was a D game.”

Ferrari says the secret to his apparent quick maths during the interview is that Abbott wasn’t in the studio but calling in “down the line” so while she was talking he was able to check the figures with his team.

He says: “If you watch [the video recording of the interview] very carefully I’m clicking a button where I can talk to my production team and I’m saying words to the effect of – and I’ll moderate my language – ‘for goodness sake I need this jolly figure damn soon because I make it ridiculous’.

“And so as there are pauses I’m saying ‘just confirm’, ‘do you agree’ and it’s like Countdown without Rachel Riley and they’re all going ‘yes, yes, that’s right’, so that’s how we were able to do it.”

He said that once a situation like that arises in an interview “you kind of concentrate on it, because you don’t want to give an inch where it will all go away”.

“So you have to make sure that you don’t suddenly open a door where they can just win the interview over and say ‘well of course I didn’t say that’ or ‘why would you say that figure’, so you are so intent.

“It’s like taking a final paper in your A-levels – you’re all over it.”

I ask him, then, if the secret to good broadcast journalism is being dogged and not letting something go? “No, the secret is just listen to the answers, always listen to the answers, that’s the key,” he says.

And what, in Ferrari’s mind, makes for a great journalist?

“You have to be inquisitive. You have to be prepared for that the minute a press spokesman or the police spokesman says everything is under control – you have to know that it’s completely a pile of shit and they are all over the place, like anything.

“You have to have a sense of humour and you also have to keep a touchstone with people so I do think, whether it’s some of the amazing foreign stories we’ve seen, whether it’s stories that have brought down England football managers, whether it’s talking to politicians, keeping a touchstone with reality is key.”

Ferrari says he was “absolutely blown away” to have been named Journalist of the Year at the British Journalism Awards – the first radio broadcaster to claim the accolade.

His work covering the Grenfell Tower fire disaster that claimed 71 lives was also mentioned by judges in awarding him the top prize.

The news industry has been criticised, including by Press Gazette, for its failure to pick up on residents’ concerns over fire safety that had been written about on a local blog before tragedy struck on 14 June.

So does Ferrari think the news industry failed in its coverage?

“We just honoured a team of journalists [at Inside Housing] who covered it. Alright, maybe the mainstream media could have done more, but yet again journalists are doing what journalists have to do, which is to hold truth to power.

“They were trying to expose this story. It’s journalists like the ones we’ve just been celebrating tonight who make so crucial the job they do in this country.”

Ferrari might be the name most associated with LBC, but his colleagues include former UKIP leader Nigel Farage and, until the end of May this year, polemicist Katie Hopkins was also on the station’s roster.

What does Ferrari think of the people he shares the microphone with each day? “Great,” he says. “If I’m running the England rugby team, I need every possible kind of player. I need the whole lot, they all bring something.”