A group of Nobel laureates have written to the British prime minister Keir Starmer urging him to intervene to help free the imprisoned writer Alaa Abd el-Fattah.

Twelve laureates including JM Coetzee, Annie Ernaux, Kazuo Ishiguro and Olga Tokarczuk have signed the letter.

“We write to you as long concerned supporters of the imprisoned writer, Alaa Abd el-Fattah,” the letter begins. “We write to you because time is running out.”

“For over 10 years now Alaa has been punished by the Egyptian military regime for his writings, for his exposure of military killing of civilians, for his theoretical work on constitutions and the law, for his acerbic wit on social media,” it continues.

Abd el-Fattah, a British and Egyptian dual citizen, has been in prison for all but a few months since 2013. A writer, blogger and software developer, he emerged as a leading activist during Egypt’s popular uprising in 2011. In 2021, he was convicted of “spreading false news” for sharing a social media post – a charge Amnesty International has called “bogus”.

He completed a five-year sentence on 29 September, but was not released, as Egyptian authorities did not count his first two years in pre-trial detention. In parliament last week, John McDonnell said that this violated international legal norms and Egypt’s domestic law.

Abd el-Fattah’s mother, the mathematics professor Laila Soueif, began a hunger strike on 30 September, surviving on sugarless green tea, water and rehydration salts.

“I am willing to go as far as it takes. I don’t think the Egyptian authorities react to anything unless there is a real crisis and, increasingly, based on experience, the British authorities seem to be the same,” she said at the end of November. “I hope it does not get this far, but maybe nothing will happen until I am being carried into the hospital completely collapsed.”

The letter was also signed by the Nobel laureates Mohamed El-Baradei, Jon Fosse, Abdulrazak Gurnah, Svetlana Alexievich, Elfriede Jelinek, Herta Müller, Peter Handke and Orhan Pamuk.

“We urge you, prime minister, to intervene before it is too late,” the letter concludes. “Not only because Alaa is a British citizen, but to reanimate the commitment to intellectual sanctuary that made Britain a home for bold thinkers and visionaries for centuries.”

In parliament, where Abd el-Fattah’s family were present in the public gallery, McDonnell said that he hopes the government will “grasp the urgency and seriousness of the situation” and “take the action necessary” to see Alaa released.

“I am extremely concerned that the British authorities remain unable to gain consular access to Alaa, let alone put pressure on the Egyptian government to release him, as he should have been on 29 September this year,” said Jacques Testard, publisher at Fitzcarraldo Editions, which published a collection of Abd el-Fattah’s work, You Have Not Yet Been Defeated, in 2021.

“His mother Laila’s life is now at risk and time is running out. Alaa is not only an exceptional writer and intellectual, but also a devoted father, brother and son, and it’s time for him to be reunited with his family after spending most of his adult life in Egyptian prisons for writing that the regime finds threatening.”

In October, Abd el-Fattah was selected as this year’s PEN Writer of courage by Arundhati Roy, who won last year’s PEN Pinter prize.