The pilot of Motherland went out last year and was one of the best pilots I've seen in recent memory. But then that's no surprise. Look at the writing credits for starters – Graham Linehan, Sharon Horgan, Helen Linehan and Holly Walsh. And a cast that includes the consistently brilliant Diane Morgan and Anna Maxwell Martin.

Motherland is one of those instant classic relatable comedies – The Office springs to mind too – where you can't believe it hasn't been done before. It probably has but not as well. All it does is follow the struggles of a group of young mothers trying to get on with life. It probably helps if you are a parent yourself, but the writing and performances are so good you could be a reclusive loner or the Pope and you would still laugh.

The first episode homes in on that perennial parenting issue, the children's party. Permanently stressed working mum Julia (Maxwell Martin) has to do the honours but is tipped off that if she gets it right she can dump her own daughter at other parties for the next year and have a break. Of course things don't go as planned - in fact what can go wrong does go wrong, from booking a racist entertainer to crap cakes to vomiting offspring.

But despite the catalogue of catastrophes, this never tips over into caricature. The parents are recognisable archetypes – from alpha mum Amanda (Lucy Punch) to slapdash Liz (Diane Morgan) to wet house husband Kevin (Paul Ready) – but never broad or cartoonish. Liz is particularly wise when it comes to party advice: "Buy four caterpillar cakes and put them all together into a human centipede cake..." 

Motherland is pretty much an object lesson in how to write a sitcom. It is mainstream but never broad. Intelligent but never high brow or smug. It features people that are so believable we feel that we know them as soon as we see them onscreen. Unlike Julia's party this is a immediate success. 

Motherland, Tuesdays from November 7, 10pm. Watch the full series on iPlayer now.