Supporters of Guantanamo Bay detainee Omar Deghayes yesterday delivered heartfelt pleas to Tony Blair outside 10 Downing Street.

A delegation from the Brighton Save Omar campaign delivered a 4,000-name petition calling on the Government to secure justice for the 36-year-old from Saltdean.

Handing over the petition to Downing Street officials, campaign organiser Jackie Chase said: "If we have any hope as a nation of preserving our good name in the world, it will be because we are seen to stand up for justice and rule of law."

Mr Deghayes, a law graduate, has been imprisoned in solitary confinement in Camp X-Ray for more than three years without being charged with a crime.

He has claimed to have suffered savage beatings, mental torture, physical hardship and religious abuse at the hands of American guards.

The Downing Street delegation was joined by Mr Deghayes' family, who fear that he could soon die as he is on hunger strike.

His sister, Amani, accused the Government of failing to act while her brother starved himself to death in Guantanamo Bay.

She said: "I would like to ask the Government to do something about my brother. He has been in detention and had very inhumane treatment and he hasn't even been charged.

"It's so desperate that he's starved himself for six weeks and he's probably not in a strong position already after three years in detention.

"We are very concerned about his welfare."

Mr Deghayes' brother, Abubaker, added: "Please, please don't let him down and don't let the world down.

"We all know it's a human right - innocent until proven guilty. Either try them or let them go."

Manus McGrogan, of the Save Omar campaign and Sussex Action For Peace, said: "We want to put pressure on ministers, and Tony Blair in particular, to demand the release of these people who have been held without trial for three years."

The Save Omar campaign will renew its demonstration on Sunday, when the Labour Party conference kicks off at the Brighton Centre.

Campaigners will be joined on the seafront by veteran Labour politician Tony Benn, who has condemned the detention of terror suspects in Guantanamo Bay without trial.

On Tuesday, The Argus presented a dossier about Mr Deghayes' plight to the Home Office. It contained articles documenting the detainees' treatment in Camp X-Ray, interviews with his relatives and calls for a fair trial from Brighton and Hove MPs and the city council.

An accompanying letter from The Argus editor Michael Beard called on the Government to lobby the US for Mr Deghayes to be either charged and put on trial, or released immediately.

A former Guantanamo Bay prisoner will be among speakers campaigning for the release of Omar Deghayes.

Moazzam Beggs will talk at the Labour Party Conference fringe meeting with Labour MP Tony Benn, Yvonne Ridley, a former journalist who was captured by the Taliban, and Jon Rogers, a Unison trade union leader.

Badges with 727, Mr Deghayes' inmate number, on them are being sold for 50p from the Peace And Environment Centre in Surrey Street, Brighton. The meeting is at Friends Meeting House in Ship Street, Brighton, on Tuesday at 6pm.