‘Marine A’ who was jailed for shooting dead an injured Taliban fighter will walk free from prison on Friday, campaigners said,
Royal Marine Alexander Blackman was originally convicted of murder but this was quashed by the Court Martial Appeal Court and replaced with diminished responsibility manslaughter last month.
Now the commando, who has spent more than three years in prison for the shooting in 2011, will leave Erlestoke Prison, near Devizes, Wiltshire.
Five judges ruled that Blackman was suffering from an "abnormality of mental functioning" at the time of the incident in Afghanistan.
His sentence was reduced to seven years, meaning he could be freed within weeks - a decision his wife Claire Blackman described as "the moment that we have all been fighting hard for".
The Justice for Marine A campaign group had repeatedly posted that the time and date of Blackman's release would not be made public due to "privacy and safety concerns".
But in a statement posted on Facebook on Thursday afternoon, it said: "We are delighted to announce that Al will finally be released tomorrow after what has been a well fought battle by you all.”
Blackman was convicted of murder at Bulford Court Martial in 2013 and jailed for life, with a minimum term of 10 years.
This sentence was later reduced to eight years. His wife Claire led a campaign for Blackman to be released, which was taken up by the Daily Mail.
In March, his conviction for murder was quashed and replaced with manslaughter on the grounds of diminished responsibility.
During the original trial in 2013, Blackman was known only as Marine A and his identity was made public after his conviction.
A spokeswoman for the Ministry of Justice refused to comment on when Blackman will be released.
The Court Martial Appeal Court found the killing was not a "cold-blooded execution" as the court martial concluded but the result of mental illness, an "adjustment disorder".
Judges described Blackman as "an exemplary soldier" before his deployment to Afghanistan in March 2011 but said he had suffered from "exceptional stressors" during that tour.
They found his ability to "form a rational judgment" was "substantially impaired".
Blackman shot the insurgent, who had been seriously injured in an attack by an Apache helicopter, in the chest at close range with a 9mm pistol.
He then quoted a phrase from Shakespeare - "shuffle off this mortal coil" - as the man convulsed and died in front of him.
The judges concluded that Blackman should be dismissed from the Royal Marines but not with disgrace.