A slim paperback caught Becky Brown’s eye as she scanned the bookshelves of an Oxfam charity shop. The cover showed a man’s silhouette with the title They in capitals.

Brown, a literary agent who was looking for something to read while staying with her parents in Bath, had never heard of the book, but its author, Kay Dick, was vaguely familiar. Intrigued, she bought it for 60 cents.

“Within the first few pages I thought, ‘This isn’t just good, this is … remarkable,’ ” she says. A quick Google search revealed that They received lukewarm reviews on publication in 1977 and disappeared into obscurity. Yet Dick, who died two decades ago, had been a key figure of the London literary scene in the Fifties, editing the writings of George Orwell and becoming the first female director of an English publishing house. She was also bisexual, wore her hair short, smoked using a long cigarette holder and often donned a monocle and cane.

“It is so unusual to find something that special that isn’t acknowledged as such,” says Brown, who co-runs the Heritage section of the literary agency Curtis Brown, representing dead authors’ estates including AA Milne, Malcolm Bradbury and Stella Gibbons.

Within months, Brown’s work to get the dystopian novella back into print led to Faber and Faber buying the publishing rights after a five-way auction. “It was a remarkable find,” says Ella Griffiths, an editor at Faber. “There’s a hunger from the public for finding voices from the past that speak to us now in a powerful, immediate and contemporary way. That’s either because of their innovative literary style or the way they lived, especially if it was unconventional, whether in terms of their sexuality, politics or resisting social norms.”

Over the past year, a wave of neglected novels by forgotten women — often with frank discussions of sex, gender, marriage and freedom — have been brought back into print. “These books all share that special element — you have to check the copyright page to double-check it wasn’t written now because it feels so fresh,” says Marigold Atkey, a publisher at Daunt Books.

“There’s a hunger from the public for finding voices from the past that speak to us now in a powerful, immediate and contemporary way.”

In the past year, sales mysteriously surged in the US and UK for Cassandra at the Wedding, a largely forgotten 1962 novel by Dorothy Baker about a gay, depressed woman in her twenties driving back to the family ranch for her twin sister’s wedding. The Hollywood star Natalie Portman called herself “one of its most ardent fans” in a post to her eight million Instagram followers.

Bea Carvalho, the head of fiction at Waterstones, says the rise of BookTok — in which people on the app TikTok share reading recommendations — and social media have fueled the trend.

“What’s been amazing about BookTok is how some books will just randomly pop up and explode almost overnight. It’s the biggest thing to have happened to bookselling for a very long time.”

In May, Vintage republished the 1968 novel The Bloater by the author and poet Rosemary Tonks, which had been out of print for nearly 50 years. In it, Min, a married audio engineer at the BBC, ponders whether to have an affair with an overweight opera singer she nicknames “the bloater”. Tonks was a fixture on the London Sixties scene; a Guardian article described her having “a white Italian sports car, a French purple velvet trouser suit, and living in a Queen Anne house in Hampstead”.

“What’s interesting about authors like Kay Dick or Rosemary Tonks is they were living with a great freedom, a kind of freedom we perhaps don’t expect people to have had at that time,” Brown says.

“These books all share that special element — you have to check the copyright page to double-check it wasn’t written now because it feels so fresh.”

The reprint of The Bloater was helped by Backlisted, a podcast presented by the publisher John Mitchinson and the writer Andy Miller, who discuss books they think should attract a wider audience. The comedian Stewart Lee, a guest on the show, said: “You stumble across something that isn’t known like this and your whole idea of the canon falls away because you think, ‘What else have they missed?’ ”

Popular millennial authors are also helping to uncover forgotten feminist classics. This summer Daunt Books brought out a new edition of All Our Yesterdays, translated from the 1952 novel by the Italian author Natalia Ginzburg. Inside is a new introduction by the Normal People author Sally Rooney, who writes: “It was as if her writing was a very important secret that I had been waiting all my life to discover.”

For Atkey, Ginzburg portrays sex and relationships in a “matter of fact way that feels very ahead of her time”. “For me, there seem to be lots of parallels between how she writes and how Sally Rooney, Megan Nolan or Phoebe Waller-Bridge write; all who have that slightly less romanticized view of sex.”

The trend bemuses Carmen Callil, who founded the female-focused publishing house Virago in 1973. “I’m delighted that these authors are getting attention,” she says. “But they were always there to be discovered; they were just not often looked at by other publishers. If publishers are doing their job, great novels always resurface.”

Tom Knowles is a technology correspondent for The Times of London