A protest has been held on the site of the new US embassy in south-west London to call for the release of the last British resident in Guantanamo Bay.
Saudi-born Shaker Aamer, 43, who lived in London, has been held at the US detention centre for almost nine years without charge.
He was captured in Afghanistan. The US says he was with the Taliban, but Mr Aamer says he was doing charity work.
About 70 people gathered at the site of the new US embassy in Battersea.
Ray Silk, from the campaign, said: "We want to publicise the terrible plight of Shaker Aamer.
"He has been incarcerated for nearly nine years in Guantanamo Bay.
"We are calling upon the UK and US Governments to make arrangements as soon as possible for his release."
Mr Aamer has written in a letter: "I am dying here every day, mentally and physically.
"We have been ignored, locked up in the middle of the ocean for many years."
Deputy Prime Minister Nick Clegg and Foreign Secretary William Hague have raised the issue with US secretary of state Hillary Clinton.
But no release date has been set.
At the time of his capture, Mr Aamer was applying for British citizenship and had indefinite leave to remain in the UK.
He lived in London with his British wife and three children. A fourth child has been born since his detention.
In November Amnesty International's UK director, Kate Allen, wrote to Mr Hague asking for him to make a public statement calling for Mr Aamer to either be "charged and fairly tried or released".