Ben Miller wants to resurrect the romcom – and Armstrong and Miller

Miller, 50, plays Murray – a workaholic husband who’s shocked when his wife Bex, played by Doc Martin’s Caroline Catz, walks out on him on her 40th birthday. He resolves to get her back and sets about a series of increasingly ludicrous schemes, combining slapstick farce with the sharp bite of heart-break. And to play Murray, he explains, he drew heavily on his own life experience – he divorced actress Belinda Stewart-Wilson, the mother of his son Sonny, five years ago.

“I’m very lucky, I had a very amicable separation and very amicable divorce, but it was still horrendous,” he explains. “This show is very close to things that have actually happened to me... so to a certain extent you’re reliving it. Sometimes that’s helpful because it grounds it in reality. But sometimes it’s not helpful because I’d be playing a scene and I’d get upset in a way that wasn’t entirely appropriate in a family sitcom. If you connect too much with the deep sadness of the situation it’s not going to be funny. It’s a fine line between catharsis and trauma, and that’s where sitcom lies.”

It’s not just the split that informs him. He met and fell for someone new – producer Jessica Parker – around the time he started as the fish-out-of-water English detective investigating murders in the Caribbean in BBC1’s Death in Paradise.

“Two weeks after I arrived in the Caribbean, Jessica found out that she was pregnant,” he gives a wry grin. “I’ve just got divorced and I’ve finally met somebody and now I’m on the other side of the world and we’re having a baby. That’s a proper curveball to be on the end of. There was a period of 18 months when I was only in the country for six months and in the Caribbean for a year. Absolutely amazing, but I thought, ‘I’ve just messed up one marriage, I don’t want to mess this up as well.’ So I knew what I had to do to get my wife back – quit Death in Paradise!”

He’d signed for three seasons and fulfilled his contract – although he was bumped off at the start of season three, providing the first case for his replacement Kris Marshall. “I constantly get people saying, ‘So what bit of spending six months a year on an island in the Caribbean with Sara Martins did you find so unbearable?’” he laughs. “But it’s all worked out fine – Kris is great, [Death in Paradise executive producer] Tony Jordan is still speaking to me and [creator] Rob Thorogood isn’t,” he jokes, “but what can you do?”

In I Want My Wife Back, Murray and Bex don’t have kids – which takes some of the sting out of their awkward inability to communicate. This was important to Miller when writers Mark Bussell and Justin Sbresni showed him the script – they all worked together on Worst Week of My Life – as he would have been uneasy with a comedy about parents splitting up.

“I have to say it’s some relief to me as a divorced parent that it’s not such a big deal any more,” he says. “There’s not the huge stigma around it that there was when I was a kid. But I think there’s a greater understanding of divorce and a greater responsibility around it – it doesn’t have to be the horrendous car crash that it would have been in the past.”

Quitting Death in Paradise succeeded in keeping his second marriage together – the couple had son Harrison in late 2011, married in 2013 and had daughter Lana in 2015. He’s now living in domestic bliss in the Cotswolds. It might appear to have hit his career, but in fact he’s never been away. You’ve just had to look in unlikely places, like presenting ITV’s science entertainment show It’s Not Rocket Science and, with his own production company, creating Horrible Science, a sister show to Horrible Histories.

Science is his passion – he started a PhD in solid state physics at Cambridge – and was also his route into comedy, when he met Alexander Armstrong in a student sketch troupe. The programmes thus have a sense of mission, he explains. “I have to say my eye is on the coming generation of scientists. I think largely the battle [to make science more accessible] has probably been lost with people of my generation and sadly, those are the people who are in control at the moment,” he says.

“But for a whole new coming generation science is for everyone. I want to get across that science is something that we all have ownership of and we can all take an interest in. We don’t all have to understand complex theories but we should have a working knowledge, like knowing your way round the engine of your car.”

But his first love is still the jokes. “My heart is in comedy, absolutely,” he nods. “Science is a hobby and I’m really into it but it’s not my job. My job is to learn about comedy and to make people laugh. Science for me is probably a bit like Danny Baker’s love of football or Rod Stewart’s obsession with train sets.”

Last year Miller was in Channel 4’s Ballot Monkeys by Andy Hamilton and Guy Jenkin, the comedy set on the various political parties’ battle buses in the run-up to the election. “In keeping with Andy and Guy’s Drop the Dead Donkey experience, we’d do this really strange thing where there was no script until we literally turned up,” he shivers. “We’d get the scripts at 11 and we’d shoot from 12 until 2 and that would be the show.”

He’d love to do an EU referendum or a US election version – although no one’s talking about it just yet. When it comes to Europe, he says he’s an inny. “I don’t think the EU is perfect and I’m enjoying the debate. We have real issues – immigration, the way the EU is funded, the human rights issue…but I want to be part of Europe. I’d like to see the argument made for greater worldwide federalism, not just the European Union. I’d like to be a hearty member of the United Nations with no security council and no veto. In a time of technological and cultural globalisation I don’t think it’s the time to be splitting up into these arbitrary nations that we’ve created for ourselves.”

Now he’s back on our screens in a comedy, he casts his mind to a possible return for The Armstrong and Miller Show, which has been on air on various channels in various guises since 1997. The most recent BBC1 series finished in 2010.

“I can’t speak for Xander [Armstrong] but I certainly feel the sap rising,” he laughs. “It feels like each series comes at notable stages of life. Things accumulate and you’re ready to let go of the characters from previous series. I think what both of us feel slightly trepidatious about is that when you start doing the show, you can’t do anything else for a whole year.

“Is Xander ready to spend all that time with me in a room, non-stop? He’ll see more of me than he’ll see of his wife. Fortunately, I can give him some advice about getting her back if she gets annoyed...”

I Want My Wife Back is on tonight at 9:30pm on BBC1