Two Palestinian writers have been refused visas to travel to the UK and speak at a festival celebrating contemporary Arab art.

The Gaza-based husband and wife writers, Ali Abukhattab and Samah al-Sheikh, were due to talk about their writing at London's ICA on 28 June but have been barred from coming – to the disappointment and frustration of festival organisers.

Omar al-Qattan, chairman of what is the second Shubbak festival, said two reasons were given for the visa refusal. One, that they did not qualify as having business reasons – "obviously they were coming for work, they were coming to do an evening in the festival" – and the other, that the authorities were not satisfied the couple would go back to Gaza.

"It is completely ridiculous. I think they are very humiliated and very disappointed. It would have been the first time they had come to the UK and London," said Qattan.

"It is very distressing. London is supposed to be an open city, a welcoming city, especially for artists, so this is very disappointing," he added.

Qattan, who in 2008 established the Mosaic Rooms, a cultural space focused on the Arab world, said other options were being explored, which may include hearing from the writers via Skype.

Shubbak is a 15-day festival from 22 June with visual art shows, concerts, theatre, talks and debates at venues that include the Barbican, Tate Modern and the British Museum.

Qattan said one aim of the festival was to give people in the UK a fresh perspective on countries that are mostly in the headlines for the wrong reasons.

"I just don't think there's enough exchange," he said. "There are a lot of things going on and a lot of Britons coming to the region and a growing and increasingly influential diaspora from the Arab world in the UK, especially London."

The first festival took place in 2011, "a euphoric time, people were looking forward to change" and very different to now, he said. "We have no idea where it is going and no sense of what is to come."

A Home Office spokesman said it was policy to not comment on individual visa cases.