Sentenced to temporary imprisonment in aconfirmed judgment, Buthas not beengranted asuspended sentenceor permitted to commute his sentence upon payment of a fine.
His family filed a petition for clemency to commute the 20-year sentence, a request that was denied by President George W. Bush in one of his final acts in office.
Mr Straw's most recent intervention was on 30 January when he contacted the chairman of the Texas Board of Pardons and Parole to urge them to commute the death sentence to a prison term and reiterate Britain's opposition to capital punishment.