An SAS sniper jailed for illegally possessing a pistol will challenge his conviction at a Court of Appeal hearing next week.
Sergeant Danny Nightingale, 37, from Crewe, Cheshire, will also appeal against his 18-month sentence at a hearing in London on November 29, his solicitor Simon McKay said.
His wife Sally, 38, said she was delighted at the news and hoped that he might be home for Christmas.
Sgt Nightingale, who served in Iraq and Afghanistan, was sentenced to 18 months in military detention after admitting possessing a prohibited firearm and live ammunition.
The father-of-two is currently being held in the Military Corrective Training Centre in Colchester, Essex.
His lawyers began their appeal against his conviction and sentence at the Court of Appeal on Wednesday.
The case has sparked a political row after Attorney General Dominic Grieve turned down a request from Defence Secretary Philip Hammond to review the prosecution, saying it would be inappropriate.
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 a 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 who had been 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.
His father, Humphrey Nightingale, said his son pleaded guilty in the expectation he would be dealt with leniently.
On Tuesday evening MPs discussed the case in the Commons, saying prosecutors should not oppose an appeal by Sgt Nightingale.
Julian Brazier, a former member of the Territorial SAS who secured the adjournment debate, said Sgt Nightingale had "risked his life for his country again and again".
Mr Brazier urged Solicitor General Oliver Heald "to review the service interest test in this case and allow the planned appeal to go through unopposed".
Tory MP Patrick Mercer, a former soldier who has sat on court martial panels, said he respected the military justice system.
But he said the treatment of Sgt Nightingale had not been in the Army's interests and could affect morale in the armed forces.