Foreign Secretary Margaret Beckett has refused to meet the family of Guantanamo Bay detainee Omar Deghayes.

Months after readers of The Argus sent postcards to the Government pleading for his release, a Brighton councillor said he has received a letter from the Foreign Office "downright refusing" to meet the prisoner's mother, brothers and sister.

Mr Deghayes, 35, a Libyan citizen with refugee status in the UK, lived in Brighton with his family for 15 years.

He was arrested in Pakistan in 2002 and has been held at Camp Delta, without charge or trial, for more than four years.

Two Save Omar campaigners, Glenn Williams and Sally Griffiths, set off on a 60-mile walk from Brighton's Palace Pier to 10 Downing Street on Saturday to protest against Mr Deghayes's detention.

The pair will be met in Brixton by fellow campaigners on Tuesday, who will then join them on the final leg of their journey before they hand a protest letter to Tony Blair.

Mr Deghayes's brother, Abubaker, said: "I'd just like to tell Mrs Beckett it's about time to bring the suffering of my brother to an end - to please do the decent thing."

Councillor Francis Tonks said he had waited months for a response to the letter he sent the Foreign Secretary in the summer, requesting she hears Mr Deghayes's family plead his case. He said: "I'm very disappointed - maybe not entirely surprised - but I think it's poor.

"It seems to me the Foreign Secretary should be putting herself out to meet someone on a humanitarian issue of this importance. It's only right that she should meet with the family and explain the Government's position. The letter says there are various meetings going on but it's a downright refusal. Hundreds of campaigners, as well as the council, are being let down."

Louise Purbrick, of the Save Omar campaign, said a thousand postcards asking for Ms Beckett's help had been printed and sent.

More were forwarded on coupons printed in The Argus in July. But neither the newspaper or campaigners have received an official response. Ms Purbrick said: "It's hopeless. We've phoned the Foreign Office and still had no reply.

"Now and again we get a letter saying there are no British nationals in Guantanamo Bay but Omar's family is British and they have responsibilities for him as a refugee."

Campaigners, including Mr Deghayes's sister Amani, protested outside 10 Downing Street on Saturday as part of Amnesty International's international day of action on Guantanamo. A chain-gang of eight men shackled in orange boiler suits marched from Parliament to Downing Street.

The Foreign Office refused to comment.