Ex-PM says she would like to write novel based on ill-fated 19th century ascent of Matterhorn

He was the British mountaineer who led the first ascent of one of the most formidable mountains in the Alps. She was the prime minister who is likely to go down in history for ultimately failing to reach the summit of her own personal Matterhorn.

Yet in her first public interview since leaving Downing Street – at a book festival in where she was asked about what book she might now find the time to write – Theresa May revealed that it was the dark rumours surrounding how four of Edward Whymper’s climbing party fell to their doom that most appealed to her.

“A number of people sadly died on the way down and there is a question as to the rope that was used. Why it broke is an interesting question,” said May, to laughter from an audience at the Henley literary festival for a talk about her career and the books that had inspired her.

Anyone seeking a parallel to her own ill-fated attempt to drag the Conservative party towards a difficult Brexit deal may be struck by the Guardian’s 1865 account of the accident, in which it is reported that after the leader of the expedition decided to press on to the summit against the expectation of others in the group, one of the party slipped and dragged three others to their demise.

Speaking as the Conservative party conference took place in Manchester, May did not point out any similarities, but suggested that her interest writing a real-life 19th century whodunnit set in the Alps was a combination of her love of detective novels and walking near the Matterhorn with her husband.

“I suppose because we like walking in the Alps I might like to write something about that,” said May, after vigorously shaking her head when asked if she was planning to write a memoir, or had kept diaries while in Number 10.

Zermatt celebrates centenary of Matterhorn's first climb: from the archive, 17 July 1965 Read more

Interviewed for an hour by Olympic gold medal-winning rower Dame Katherine Grainger, nothing had changed when it came to May’s famous reticence. Her stack of cookbooks now numbered 150 but she couldn’t name a favourite. She also hadn’t read David Cameron’s recently published memoirs. Instead, detective fiction in the form of an Inspector Montalbano novel was currently beside her bedside.

One of the more striking revelations about a book that had shaped her centred on Rachel Carson’s Silent Spring, the 1962 text that is sometimes credited with laying the foundations of the modern environmental movement.

May had not read it but said that it had shaped her mother’s thinking. May said: “I know that my mother was very taken by it and it impacted on her, and that sort of fed through to me. In a sense it was quite unusual for vicar’s wife in north Oxfordshire to read a controversial book like that but I am very glad that she did.”

Rather than awakening May up to a radical green agenda, however, Silent Spring seemingly had a more abstract effect of making her “cognisant of the environment in which you are operating” while also showing the impact a book could have.

Adding that she didn’t believe her mother would have been “demonstrating on the streets”, May expressed regret that not enough attention had been paid to the issues raised by Carson.

“I always say now that on climate change, my husband and I enjoy walking in Switzerland in the Alps and there is one particular place where over the years we have been going there we have been seeing the glacier retreating year by year and you just think: something is happening, something is changing here and we need to think about how we manage it.”

Meanwhile, one of the few moments when May was questioned about contemporary controversies came when she was asked if she was surprised by the reaction to her honours list, which bestowed a knighthood on Geoffrey Boycott, the the former England cricket captain.

The honour sparked controversy owing to his conviction in a French court more than 20 years ago for assaulting his then girlfriend.

“Well I put my honours list together believing that there were people who I believed should be honoured in that way,” said May, shifting uncomfortably in her seat.

“There was reaction in a variety of ways to my resignation honours. You just put together the names that you thought were appropriate.”