A judge has found "room for argument" that a Surrey family have been wrongly refused a conditional posthumous pardon for a WWI soldier shot for cowardice.
Shot at Dawn is modelled on Pte H Burden who was shot aged 17
The family of Private Harry Farr of 1st Battalion West Yorkshire Regiment have fought for 13 years to clear his name.
Mr Justice Stanley Burnton said the point was worthy of decision in court, but found no grounds to challenge the refusal of a full free pardon.
A full hearing is expected to take place in the next few months.
After the hearing at the High Court, Pte Farr's granddaughter Janet Booth, 63, of Farnham, Surrey, said: "At least now there is a little ray of hope.
"We believe Harry was innocent. He was a victim of shell shock who was never given a fair trial."
All pardons refused
Mrs Booth, who was at the Royal Courts of Justice with her husband, Jim, said: "It was a dreadful stigma. For a long time his name vanished off the face of the earth in the family - nobody talked about him."
She said she was taking legal proceedings on behalf of her grandmother, who has since died, and her 91-year-old mother, Gertrude Harris, of Box Tree Lane, Harrow Middlesex.
Pte Farr was 25 years old when he was shot at dawn during World War I.
Last June, defence secretary Geoff Hoon refused to grant a pardon of any sort.
At the High Court on Monday, the judge said the family lacked legal grounds to challenge refusal of a full free pardon which would signify that he was "morally and technically innocent" of the offence of "cowardice in the face of the enemy".
Message of condolence
But he said the point that a conditional pardon was wrongly refused was worthy of a decision by the court, indicating that the military authorities should not in all the circumstances have imposed the death penalty.
Lawyers representing the family said it was "unreasonable, flawed and wrong in law" not to grant a pardon of some kind.
After the execution, an Army chaplain's message to Private Harry Farr's widow said "a finer soldier never lived".
The chaplain who attended the execution sent the message of condolence to his widow via a local vicar.
He told the family Pte Farr had refused a blindfold when he was shot in October 1916.
More than 300 British and Empire soldiers were court-martialled and executed during the First World War.