I'm a swearer. I practically grew up on the Karabar netball courts, an environment where stevedores and old-school sailors would get the vapours and faint at the language, and I've carried that need to liberally pepper the ragout of my everyday language with swear words into adulthood and through my career.

And so to Wicked Little Letters. It seemed like a committee had been formed to design a film to best appeal to my sense of humour.

In a small British seaside town in the 1920s, Edith Swan (Olivia Colman) lives with and plays a role caring for her ageing parents Edward (Timothy Spall) and Victoria (Gemma Jones).

Mr Swan is a piece of work, full of priggish Christian indignation about everything and everyone, and especially about the rough hard-drinking Irish widow Rose Gooding (Jessie Buckley) who has moved in next door.

When Edith starts receiving shocking hand-written letters delivered to the house, with no sender's name written on the envelope, expressing in the foulest language Edith's character flaws, Mr Swan immediately assumes the author is Rose.

Rose has her own worries including bringing up daughter Nancy (Alicia Weir) and managing her interracial relationship with boyfriend Bill (Malachi Kirby) in a community where she seems to press every button for the small self-righteous misogynistic white Christian community.

Rose is delighted to hear about these letters that just keep coming, openly laughing at the foul language. This is too much for Edith's father who brings in the local constabulary and has Rose arrested for indecency charges as their apparent author.

The police, of course, immediately believe the word of Mr Swan over the protests of innocence from the Catholic single mother and Rose's case goes to trial, a court hearing sensationalised by the London newspapers. While Rose is out on bail the letters increase in their tone and number, now being sent to many other notable figures in the community. It does not look good for Rose, except that there is a lone voice who believes her.

Police officer Gladys Moss (Anjana Vasan) is usually relegated to tea-making and other mundane duties in the local police station. She is brought in to hear statements in this unusual case with women as the victim and the culprit, but some things aren't ringing true.

Screenwriter Jonny Sweet exhumed this real-life story of the "Littlehampton libels" from the news archives, and it gives a great series of parallels to our modern dynamic, with moral prudery from a misogynist society. The more things change.

There is something so delicious about Olivia Colman eloquently delivering the foulest language in her beautiful crisp Shakespearean voice. It is hilarious and the preview audience I saw the film with were falling about and still sniggering minutes after some of the bigger comedy moments had moved on.

The film's costuming and set design add to that sense of deliciousness so well, that obscene language juxtaposing so jarringly against beautifully cut era clothing and pinned hairdos.

Spall is wonderful as the mean-spirited father, and by wonderful I mean thoroughly believable as such an awful man.

Director Thea Sharrock encourages a lack of nuance at all times, paying service to the comedy, and though the film slows towards its third act, it is a very enjoyable diversion.