The case of a Worcestershire soldier who was executed by firing squad in the First World War has been described as a "grave injustice" which must be corrected.

Campaigner, historian and senior university lecturer at Trinity College Dublin Dr Gerald Morgan says the family and supporters of Sgt John Wall, from Tenbury, have the best case of all those trying to clear their loved ones' names.

"Sgt John Wall's is by far the best case because he had an exemplary record of fighting through all the major battles.

"It is an absolutely extraordinary case.

"He had done nothing to deserve it.

"A lot of other cases seem to be cases of shellshock where they have just had enough.

"But there is nothing against him."

Sgt Wall was in the 3rd Bn Worcestershire Regiment fighting in France when he and two others became separated from their battalion.

They took cover from enemy fire until they felt it was safe to reunite with their company.

Wall was charged with desertion and, despite an exemplary record for discipline, combat and good character which had secured his promotion to sergeant, he was found guilty and then he was executed on September 6, 1917, - a few days before his 22nd birthday.

British and Imperial forces executed 346 men - mainly English - during the First World War.

Dr Morgan, who was born in the Forest of Dean, but has lived in Dublin for 35 years, has been studying the Shot At Dawn cases for about eight years.

"There were 26 Irish soldiers shot by their own side in the First World War. The campaign to clear their names is gathering a lot of momentum over here.

"The whole thing is not going to go away because the families have suffered a tremendous amount of misery. These young men were volunteers fighting for their country.

"This matter will not rest.

"There is no question that a grave injustice has been done to John Wall and it must be corrected."

He says the British Government should followed the example set by the New Zealand Government which has exonerated all its soldiers executed in the First World War and posthumously honoured them with medals for their service.