Literature's gatekeepers have opened a chink, as HarperCollins' major science fiction and fantasy imprint, Voyager, flings wide its doors to submissions from writers without an agent for the first time in more than a decade.

Voyager, home to names including George RR Martin, Robin Hobb and Raymond E Feist, is preparing to be inundated with manuscripts when it opens to unagented submissions on 1 October, offering writers the chance to submit full, unagented manuscripts for a limited two-week period. The initiative will run until 14 October, with Voyager hoping to find 10 to 12 new authors which it will publish monthly, in digital format, over the course of a year.

Despite HarperCollins's declared policy of refusing unsolicited manuscripts, Voyager already receives 50-100 agented submissions a week. In anticipation of a huge increase, editors from the UK, US and Australia are lined up to help out with the extra reading.

"I think there's going to be an absolute deluge," said editor Amy McCulloch. "But we are seeing all the time the new and exciting ways of discovering new talent, and we feel it is the right time."

Earlier this week HarperCollins paid a substantial sum for 18-year-old Abigail Gibbs's first novel The Dark Heroine, which was discovered on social reading website Wattpad. McCulloch would not discuss what advances, if any, would be paid to unagented authors signed by Voyager in October.

The publisher is looking, it said, for writers "with fresh voices, strong storytelling abilities, original ideas and compelling storylines". Both adult and young adult fiction will be considered, but particularly novels in the epic fantasy, science fiction, urban fantasy, horror, dystopia and supernatural genres.

Each author to be discovered by Voyager will receive full editorial, marketing and sales support across the UK, US and Australia, when their novels are published in ebook format. "It's going to be e-only to begin with but we are definitely not closing the door to print if something really takes off," said McCulloch. "This is going to be about finding new voices, and seeing what really works with the audience, what captures their imagination … It's not something we could do all the time, but we want to make sure we're not missing out on new talent."

Literary agent John Jarrold said that other publishers were also considering similar moves. "One one level it could be looked at as similar to the way I used to publish books as paperback originals, so the authors could prove they could be published at that level before moving up to hardbacks," said Jarrold, a former science fiction and fantasy editor. "There are so many changes going on that it will be interesting to watch how this develops … It's another way in to the marketplace. I'm not specifically positive or negative, but it's early days, and you have to be open to everything because things are changing so quickly."