IMAGINE the scene: a beautiful summer’s day on the Sussex coast, the beach filled with holidaymakers – fathers, mothers and children bathing in the sea and having fun.

Now imagine that those same people were actually attending the annually held Blackshirt Summer Camps organised by the fascist leader Oswald Mosley, where women in floral frocks would give out leaflets for the British Union of Fascists and members would march through Sussex villages and give the Nazi salute.

It really did happen in Sussex in the 1930s and the phenomenon is the inspiration for The Faithful, the second novel by the author Juliet West, which is published in paperback this month.

Juliet, who grew up in Worthing and lives in West Sussex with her husband, BBC football commentator Steve Wilson, and their three children, stumbled across this “unsavoury” part of history, as she calls it, when she was studying at Chichester University for her MA in Creative Writing. “My desk was in the library’s history section,” she says. “And I came across a book called Blackshirts-on-Sea: A Pictorial History of the Mosley Summer Camps 1933-1938, where hundreds of ordinary people of all ages would come the camps at Selsey, Pagham and West Wittering. The photos showed Fascist drum parades and camp fire concerts with Mosley and his acolytes posing in bathing trunks and they were quite bizarre.

“What struck me was the number of ordinary women in quite sinister pictures lining the streets of Bognor Regis giving the salute.”

Intrigued, Juliet visited the scene of one of the camps in Aldwick, West Sussex, and wondered what its residents would have thought of the Blackshirts descending on their exclusive seaside haven. “Locals must have been perturbed by the drum parades, the fireside singing, the boxing matches and the sea-bathing sessions,” she says.

Above: Juliet West/picture: Kelly Hill

Below: her novel The Faithful  

Above: Before The Fall by Juliet West

Her trip inspired the basis for The Faithful. “I imagined a girl from one of the big houses watching the teenage fascist cadets on the beach,” she says. “She is 16 and bored. The Blackshirts – dismissed by her Bohemian mother as ‘cranks’ – strike her as daring, dangerous even.”

The novel opens in July 1935 in the village of Aldwick on the Sussex coast, where 16-year-old Hazel faces a long, dull summer with just her self-centred mother Francine for company.

But then Francine decamps to London with her lover Charles and Mosley’s blackshirts arrive in Aldwick. Hazel’s summer suddenly becomes more interesting as she is befriended by two very different people: Lucia, an upper-class Blackshirt passionate about the cause, and Tom, a young working-class boy increasingly scornful of Mosley’s rhetoric, much to the alarm of his Mosley-worshipping mother. For Hazel, flirting with the Blackshirts is a form of rebellion.

The book follows Hazel’s life to autumn 1936 when she is now living in London and has grown up fast over the past year. Then an encounter with Tom sends her into freefall. She has secrets he must never learn – yet Hazel isn’t the only one with secrets.

“If there’s something I do not understand, I’m intrigued,” says Juliet, who studied history at Cambridge University and trained as a newspaper reporter, working for newspapers and magazines in Dorset, Hampshire and London. “If it makes us uncomfortable, it gets swept under the carpet. I want to write a great story that’s interesting and is based on real history.”

Researching the Blackshirts took Juliet to the British Library, where she delved into the literature and propaganda of the time, leafing through old copies of The Blackshirt (the weekly newspaper of Mosley’s British Union of Fascists).

“I knew I would find this literature disturbing, but – given that this was a legal and widely distributed publication – I was truly shocked by the violence and vitriol of the paper’s anti-Semitism,” she says. “The novel moves from the beaches of Sussex to the battlefields of civil war Spain, so I also researched the Spanish Civil War, as one of my characters is a communist who joins the International Brigades. Personal accounts proved the most vivid.”

She describes The Faithful as a “love story”. “It’s a story about families and about motherhood – different variations of motherhood in it.”

Motherhood is also a strong theme in her first novel, Before The Fall, which was published in 2014. Set during the First World War, it is inspired by a true story and tells how a young mother whose husband is away at war is faced with the most dangerous of temptations when she meets Daniel.

“I first came across the real life story in my 20s when I was working in Features on a newspaper,” says Juliet. “I researched the background to a story for a piece on love stories of the First World War and it was the story of a soldier’s wife in London’s East End who fell in love with another man while her husband was away fighting.

“For years, that story haunted me and I knew I wanted to tell that story. I’ve always been interested in history but what interests me about the war is not the battle fields or the politics, it’s the impact on families. That’s what I want to explore. It’s right that we have books about battles and war heroes but I want to show the human side.

“Like many people, I’m of that generation where the war is within my parents’ living memory. Although it is in the past, it is still with us. Yet it’s hard for us to imagine the hardships that people went through.”

She adds: “I felt pleased that I could tell the story of the soldier’s wife and her lover. At the time, they were treated very harshly and ostracised for something we would not see as a crime today. I felt privileged to tell their story, to exonerate them.”

The Faithful by Juliet West is published in paperback by Pan Macmillan on July 26, priced £7.99.