Clashes between generations are a fertile ground for comedy, which Only Child farms expertly.

Bryce Hart’s script is packed full of jokes, which Gregor Fisher and Greg McHugh deliver with such natural ease that they never feel forced. Beneath the gags, the show has plenty to say, too, about the strains of coming to terms with an ageing parent, yet does so with the lightest of touches.

We first encounter the recently widowed Ken on the phone to his middle-aged son Richard, trying to get some help with his malfunctioning iPad. It could be a clichéd situation, but Ken’s technical incompetence feels real, as does Richard’s tolerant but exasperated response. Then comes a great punchline.

Ken is a wonderful comedy oddball who could well earn his place in the pantheon of great sitcom characters. With a veneer of respectability that Fisher’s 1990s alter-ego Rab C Nesbitt never had, he’s nonetheless amusingly dotty in every way.

He’s firmly set in his ways, refusing to believe he needs more help in his life now, despite mounting evidence to the contrary in his bizarre behaviour. But the line between eccentricity and senility is a fine one, when you’re dealing with a man who trousers sausage rolls from a wake, just in case.

Meanwhile, McHugh’s Richard is an actor from London forced back in to small-town life in Forres, near Inverness, where there’s nothing bigger to occupy a neighbour’s mind than who’s got the right bins. He’s treated like a bit of a local star thanks to his supporting role in a TV crime drama, but his career certainly isn’t going as well as he would like. Especially when his agent, voiced by Jennifer Saunders, calls in with some news from her Soho wine bar.

There’s a colourful cast of supporting characters too, from the local petty criminal to the worryingly crime-obsessed duo who run the pub. And while Richard’s essentially the straight man in the classic odd-couple relationship with his doolally dad, girl-next-door Emily (Amy Lennox) is an even  smart cookie, savvy to what’s going on more than Ken and his supposedly cosmopolitan ways.

While the comedy can be very jokey and even slapstick – witness Ken trying out a bed at the end of episode one – it’s grounded by a warmth, affection and naturalistic performances. The chemistry between father and son is strong, and the feeling that their relationship is shifting as Ken ages palpable.

With an emotional heart and a truly impressive gags-per-minute rate, the BBC deserve to have a hit on their hands with this rarest of Beast – a delightful and funny new comedy.

• All episodes of Only Child are on iPlayer now, Episode One airs on BBC Scotland at 10pm tonight and BBC One at 9.30pm tomorrow.