The more appeals that take place... the greater the likelihood is that we will get the decision we want

Amnesty International

Amnesty International says Mr Blair has been silent over case of Housel, 43, who faces execution on Tuesday, 12 March.

The protest, which saw campaigners wave banners of a 'gagged' Mr Blair, follows a personal plea to the governor of Georgia by Jack Straw.

The foreign secretary - who has met Housel's mother Lula Mae Pellerin - was told the governor had no powers to intervene.

Goodwill

Amnesty said: "The feeling is that the more appeals that take place from the more influential people, the greater the likelihood is that we will get the decision we want."

Tracy Housel is due to be executed on 12 March

Mr Blair had a lot of goodwill in the US, which he should use to help a British citizen, a spokesman added.

The appeal for action comes after Housel told of his remorse in an interview with BBC News Online.

He said he regretted raping and strangling hitch-hiker Jeanne Drew during a two-week homicidal spree in 1985.

"It's a bizarre thing to know the exact date and minute of your death in advance and be totally powerless to stop it."

He added: "It's hard not to play the 'what if' scenario. If my dying would bring her back, I would happily go to my death tomorrow."

Initial trial 'unfair'

Housel was born in the British territory of Bermuda and has spent 16 years on death row since his conviction.

Without a reprieve he will become the first Briton executed in the US since Nick Ingram was put to death in 1995, also in Georgia.

Lawyers argue his initial trial was unfair because the jury heard evidence of three other crimes allegedly committed by him - even though Housel had never been convicted of these "offences".

They say his young and inexperienced lawyer wrongly advised him to plead guilty, depriving him of the defence of insanity.

Housel has also been found to suffer from hypoglycaemia - a medical condition which can bring on psychosis.