Lawyers for an SAS sniper jailed for illegal possession of a weapon are to lodge their appeal.
Sgt Danny Nightingale, who served in Iraq and Afghanistan, was sentenced to 18 months in military detention after admitting possessing a prohibited firearm and ammunition. The father-of-two is currently being held in the Military Corrective Training Centre in Colchester, Essex.
His lawyers will launch an appeal against his conviction and sentence at the Court of Appeal this afternoon, as well as applying for bail.
The case has sparked a political split on Monday after Attorney General Dominic Grieve turned down a request from Defence Secretary Philip Hammond's request to review whether proper consideration was given to whether the prosecution was in the public interest.
The move left Sgt Nightingale's wife Sally "disappointed" after Mr Hammond's request had given her "real hope" that her husband could be home for Christmas.
She said she hoped the Attorney General would at least consider reviewing any decision by the Service Prosecuting Authority to oppose the appeal and seek a re-trial if her husband's conviction was quashed.
Although the Ministry of Defence (MoD) is unable to intervene directly in the legal case, it is understood that Mr Hammond's personal view is that it is in the public interest for any appeal to be heard as a matter of urgency.
David Cameron was said to be sympathetic to Sgt Nightingale and his family but his official spokesman said: "This is a case where due process has to be followed."
Sgt Nightingale pleaded guilty at court martial to illegally possessing a 9mm Glock pistol which had been packed up and returned to him by colleagues after he had to leave Iraq in a hurry for the funeral of two friends killed in action. He also admitted possessing ammunition.
The court heard that the gun was a gift from Iraqi soldiers he had been helping to train but Sgt Nightingale, who had suffered medical problems affecting his memory, said he did not remember having it.