Controversial Scottish comedian Frankie Boyle has gone on hunger strike in solidarity with a Britain-based prisoner at Guantanamo Bay, writes Judith Duffy.

Boyle is one of a number of people undertaking a week-long fast to raise publicity for the plight of Shaker Aamer, who has been held at the detention camp since 2002.

In his online blog, United States-based British lawyer Clive Stafford Smith, the founder and director of legal action charity Reprieve, wrote that he had spent the past week with no food, with Boyle taking over from him.

He said the comedian's high profile would be able to highlight what was happening at Guantanamo.

Stafford Smith said: "One purpose of these symbolic actions is to provoke debate, to press President Obama to fulfill his post-election promise [to close Guantanamo Bay], and I suspect Frankie is better at doing that than I am."

He said that the actress Julie Christie has also just volunteered to take part, and he added: "We live in a celebrity world, and there is nothing wrong with that so long as celebrities use their notoriety for a good purpose."

Aamer, a father of four, is a legal, permanent resident of the UK and is married to a British national. He has long been cleared for release by the US and has never been charged with a crime in the country, according to Reprieve.

Boyle has been updating his progress to his 1.5 million followers on Twitter.

A message yesterday said: "OK, so day 4 of not eating feels a bit f**king grim."