An award-winning author has delayed receipt of £50,000 in prize money until its sponsor shares a plan to reduce “fossil fuel extraction and increase its investments in renewables”.

Richard Flanagan won the 2024 Baillie Gifford Prize, for his memoir Question 7, becoming the first author to win the award and a Booker Prize for fiction, which he took in 2014 for The Narrow Road To The Deep North.

Flanagan, 63, who is currently on a six-day trek in the Tasmanian rainforest, said in a pre-recorded message, accepting the award, that he was “grateful” to receive the non-fiction prize and was “honoured” to be named in the shortlist.

But he said his “soul would be troubled” if he did not speak out about the threat of the climate crisis.

In the message, screened at a London awards ceremony, the Australian said: “At a time of great duress for writers, Baillie Gifford’s sponsorship matters, because it helps keep alive not only this prize, but literature in this country, and I thank them for that larger gift to us all.

“Yet my soul would be troubled if I did not say that the very rainforests and heathlands in which I am am camped tonight, unique in the world, are existentially threatened by the climate crisis.

“And were I not to speak of the terrifying impact fossil fuels are having on my island home, that same vanishing world that spurred me to write Question 7, I would be untrue to the spirit of my book.”

He went on to say that in “becoming the beneficiary of Baillie Gifford’s generosity” he would “give something in return” to the investment firm, which he said was “something perhaps more valuable than money, a perspective that may otherwise be absent from their executive discussions”.

He continued: “The world is complex, these matters are difficult, none of us are clean, all of us are complicit.

“Major booksellers that sell my books are owned by oil companies, major publishers that publish my friends are owned by fascists and authoritarians.

“No-one tonight should regard my words as criticism of Baillie Gifford, but its opposite, it is belief in Baillie Gifford’s good faith, and the seeking of a way forward.

“When we stumble, when we weary, it sometimes helps to have a friend to urge us on to our destination.

“I would welcome an opportunity to speak with Baillie Gifford’s board both to thank them for their generosity and also to describe how fossil fuels are destroying my country.

“How, as each of us is guilty, each of us too bears a responsibility to act, a writer, a fund manager.

“I would urge Baillie Gifford to act on its own publicly stated conviction that it sees no future in hydrocarbons, by sharing with the public a plan to reduce its already minimal direct investment in fossil fuel extraction and increase its investments in renewables.

“In accepting this prize, and the prize money that goes with it, I have a small caveat, I will delay taking receipt of the money until the day that plan is announced.

“And on that day I will be grateful, not only for this generous gift, but for the knowledge that by coming together in good faith, with respect and goodwill, it remains possible yet to make this world better.”

It came as Pulitzer-Prize-winner Viet Thanh Nguyen, who was shortlisted for the prize, said he would be donating his £5,000 prize from Baillie Gifford to a charity for Palestinian writers, urging it to divest from companies involved in Israeli occupation and the fossil fuel industry.

Baillie Gifford faced criticism earlier this year after 50 writers joined a group of climate campaigners in threatening to boycott events sponsored by the firm in 2024, unless it divested itself of billions of investments or organisers found a new sponsor.

A number of book festivals and arts events pulled out of their partnerships with Baillie Gifford, including the Edinburgh International Book Festival, Hay Festival and Wigtown Book Festival.

In response to Flanagan’s criticism, a Baillie Gifford spokesman said: “Congratulations to Richard for winning the two most coveted accolades in the realm of literature.

“We look forward to welcoming him to Edinburgh and continuing the conversation.”