The poet laureate, Carol Ann Duffy, has added her voice to those of other leading international cultural figures who have joined human rights campaigners in calling for the release of Ashraf Fayadh, pictured, the Palestinian poet and artist facing execution in Saudi Arabia.

Referring to the Hadith, the sacred text that reports what the prophet Muhammad said or approved, Duffy said: “The world can only remind the Saudi authorities of the words ‘My mercy overcomes my wrath’ – and where they are said to be written.”

More than a dozen organisations for artists, writers, musicians and freedom of expression from the UK, North America and Africa – including Index on Censorship, literary association PEN International and the International Association of Art Critics – have signed a joint statement condemning Fayadh’s conviction for renouncing Islam, a charge which he denies.

The statement, which will be delivered to the Saudi embassy in London by English PEN on Friday, says: “We believe that all charges against him should have been dropped entirely, and are appalled that Fayadh has instead been sentenced to death for apostasy, simply for exercising his rights to freedom of expression and freedom of belief.”

Jo Glanville, director of English PEN, said: "We are shocked by the news that a Saudi court has ordered the execution of poet Ashraf Fayadh. This is yet another example of the Kingdom’s complete lack of respect for freedom of expression and its persecution of free thinkers. We call on the Saudi authorities to release him immediately and unconditionally, and urge our own government to speak out on his behalf as a matter of urgency."

Amnesty International is lobbying for Fayadh’s release, and denounced his lack of legal representation as a violation of international and Saudi law. In a message to supporters, Fayadh said: “I am grateful for everyone working on my behalf. To be honest, I was surprised because I felt alone here. I am in good health. I’m struggling to follow all the developments. People should know I am not against anyone here, I am an artist and I am just looking for my freedom.”

Fayadh was originally sentenced to four years in prison and 800 lashes for apostasy by a court in Abha, a city in the south-west of Saudi Arabia in May 2014. He has denied the charges, which arose from a book of his poetry and a complaint lodged by a man who accused him of making blasphemous remarks during an argument in a cafe in the conservative city.

After his appeal was dismissed, Fayadh was retried and a new panel of judges ruled that he should be executed. He was given 30 days to appeal against the ruling.

Background: Saudi Arabia sentences poet to death