The possibility that a British-Egyptian pro-democracy activist on hunger strike could die while the Cop27 summit takes place in Sharm El-Sheikh is “a terrifying prospect”, a friend and star of The Crown has said.

Actor Khalid Abdalla likened detained writer Alaa Abd El-Fattah to suffragette Emmeline Pankhurst, saying he represents the “progressive fight in Egypt”.

Abdalla, who plays Dodi Fayed in The Crown, said he wanted to be on the “right side of history” in speaking up for his friend.

The activist and father has spent most of the past decade behind bars in Egypt and last December was sentenced to five years in prison after being accused of spreading false news.

He has been on hunger strike in prison, eating only 100 daily calories for the past 200 days, and will stop drinking water as the summit begins to escalate his protest.

Prime Minister Rishi Sunak, who is in Egypt for the major climate summit, has written to Mr Abd El-Fattah’s family saying he was “totally committed” to resolving the case, which he described as “a priority for the British Government both as a human rights defender and as a British national”.

Mr Abdalla said the reason for his friend’s detention is “completely absurd”.

He told ITV’s Good Morning Britain: “The actual reason technically for him being in prison is for sharing a Facebook post, it’s completely absurd. A Facebook post about the torture of a fellow prisoner.”

He said the writer and his family represent the “progressive fight for democracy, and social justice and a better world”.

He said it is crucial that Mr Abd El-Fattah is freed.

He told the programme: “Right now we’re facing the possibility of his death in the coming days before Cop27 ends. It’s a terrifying prospect.”

He added: “All 120 world leaders are descending on Sharm El-Sheikh right now. If all of them can’t result in Alaa being released from prison, then what hope have we got of saving the climate?”

On his support for Mr Abd El-Fattah, the actor said: “You’ve got to be on the right side of history. If you knew that there was an Emmeline Pankhurst in prison right now and you knew that there was a chance for her to get out, what would you be doing?”

In his letter to Mr Abd El-Fattah’s family, Mr Sunak described Cop27 as “another opportunity to raise your brother’s case with the Egyptian leadership” and said Middle East minister Lord Ahmad would update the family on negotiations after the summit – which finishes on November 18.

Mr Abd El-Fattah’s sister, Sanaa Seif, said she was worried her brother, who looked “very, very frail” with “sunken eyes” last time she saw him in August, would die before the end of Cop27.

The Foreign Office has said ministers are “deeply concerned” about the incarceration of Mr Abd El-Fattah and they are “working hard” to secure his release.