Two of the artists featured in a new exhibition will definitely not be present on the opening night. Instead of mingling with fellow artists in London’s West End, they will each be spending the time in a high-security cell in a penitentiary in the US.

The pair, Antonio Guerrero and Gerardo Hernández, are members of the so-called Miami Five, who were jailed in the US in 2001 at the conclusion of a controversial trial. The five were Cubans who had infiltrated militant anti-Castro exile groups in Florida that were suspected of carrying out sabotage attacks aimed at destabilising Cuba.

The men were sentenced in Miami to terms varying from 15 years to “double life” on the grounds that they were acting in the US as agents of a foreign power. Their defence was that they were seeking to disrupt terrorist attacks which, the Cuban government claims, have caused hundreds of deaths, most recently in a 90s bombing campaign in Havana hotels and clubs aimed at derailing the booming holiday industry.

Lawyers for the five argued unsuccessfully that a fair trial in the toxic anti-Castro atmosphere of Miami was impossible. In 2011, one of the five, René González, was released and remains on parole in Florida…