Toby Jones shuffles into the café in Clapham where we are meeting. He’s wearing a duffle coat and a hat and carrying a rucksack. He looks just like one of those unsung characters that he specialises in, the kind of person you don’t take much notice of unless you have to.

Today we are talking about his new ‘vehicle’ (sorry), Don’t Forget the Driver. It’s an everyday tale of an everyday coach driver (Peter Green) from Bognor Regis, his daughter Kayla, who turns ennui into an artform, and mother Audrey, who’s going downhill fast with Alzheimer’s. It is going to twang the nation’s heartstrings.

What makes it different is that it is Jones’s first go at writing a TV comedy — or co-writing one. He’s teamed up with Tim Crouch with whom, it turns out, he shares a love of coaches and driving them.

Crouch began with two things he wanted to explore. ‘He comes from Bognor and loves the place. There’s a non-stop webcam on the pier and he goes and waves into it so his brother in Canada can see him. To begin with I wasn’t really interested in Bognor, but we were both fascinated by coach driving.’

Crouch and Jones took an interesting approach to research: day trips to Bognor featured heavily as did hanging out near the Butlin’s that dominates the town. And then there were a few booze-and-fag coach trips to northern France.

‘I realised how much hanging round there was and how the coach drivers felt threatened by the threat of fines if they brought back a stowaway.’

Armed with the trips and a new love for Bognor, Jones and Crouch fairly raced through the script. ‘We didn’t want to mention the “migrant” word or the “refugee”word or any of the usual words used; we wanted to write about a coach driver who gets out of his depth. We wanted to write about families and love and the care people have for each other.’

The show gives them a chance to explore the odd glamour of the coach driver. Each day taking a diverse group of strangers to a different part of the country. ‘It was a way that we could celebrate Britishness in all its diversity.’

And here we have Jones’s unusual mission, perhaps spurred on by his own charming ordinariness. It was C.S. Lewis who said that there’s no such thing as an ordinary person, a thought echoed by Peter Brook whose advice has stayed with Jones over the years. ‘He encouraged me to respond differently to other people, to see that each person is way bigger than an actor can ever capture. There are always more rooms in their heads, more to explore.’

And Jones has made a habit of giving a bit of glory to the people we’d otherwise miss — gentle everyday heroes. Like Neil Baldwin — Stoke City kit-man extraordinaire who he brought to life with such tenderness in Marvellous. But where does it spring from, this urge to add a bit of dignity to everyday life?

‘I grew up in an acting family. I watched my parents. I thought I’d grow up and be someone who worked with ideas — that’s what I thought when I was at university. But there’s a family trait and I’ve inherited it. We are interested in people’s stories. We can’t help it. It runs in the blood. And so, the older I get, I find myself more and more interested in other people.’

We head back to the coach and the show and the backdrop of Bognor. Don’t Forget the Driver is oddly tense, sinister even. There’s a body washed up on Bognor beach (spotted by John’s suntanned twin brother — also played by Jones — from Australia on the Bognor pier webcam). Then our hero discovers a stowaway aboard his coach when he gets back from Calais. There’s one of those make-or-break moments that most lives seem to have. Leave her in the hands of the traffickers or open his coach to her and face the consequences? What do decent people do when they are thrown into the moral frontline? The show is truly one fit for our times. How can we stand by? It extends the usual everyman role into something meatier and more nuanced.

Jones knows how to be busy. He never stops. In just a few years we’ve seen him in Dad’s Army (Captain Mainwaring), Tinker Tailor Soldier Spy (Percy Alleline), Journey’s End (Private Mason) and, of course, as Lance in Detectorists. He’s also the voice of Dobby the house elf in Harry Potter. Is the busyness a defence, a fear of the work drying up and having to go back to those small roles before the mayhem started? Looking at his credits there are quite a lot of parts like kitchen boy, civil servant and doorkeeper. Jones has come a very long way from playing a forgettable Sgt Protheroe in a single episode of Lovejoy.

‘Actors often say this to me. They ask when I’m going to take a holiday. I wonder why. Why would I take a holiday when what I do feels like a holiday? When you’re unemployed, that’s when you need a holiday. That’s really tough.’

But perhaps there’s an alternative career. If the acting dries up. What about Toby Jones, coach driver, pottering around with a clip-on tie? Uniform, peaked hat and dispensing the milk of human kindness, like Peter Green?

‘When you’re at school, you take the piss out of coach drivers. When you grow up you don’t really recognise that they are there. But it’s a really responsible job.’

They can’t screw up. They can’t be tired when they drive. They have responsibility for the safety of people. ‘They are calm. They have to be calm. It’s what you need in comedy as well. You have to be calm.’

And what about it for Jones if he gets a bit cash-strapped? ‘Maybe.’ Perhaps what we really need is more coach drivers who switch into stand-up.

For now, he loves being an actor. ‘Just for this show, I got to take my test for a coach driving licence, which was exciting. When I played Truman Capote, I learned to make a completely different shape for my mouth so I could get the accent. You learn all the time. It’s a great life. Serious fun. Serious.’

He still thinks about that role in the 2006 Capote biopic Infamous. It switched his career up a gear, took the little guy with the face made for character acting from supporting role to leading man. ‘I was shit-scared. Playing an iconic character with these very experienced American film actors.’

He looks at me. ‘It was terrifying, but then all the best roles are.’ Even playing a coach driver from Bognor Regis.