Three judges at the Court Martial Appeal Court in London rejected the application by Sergeant Danny Nightingale, 39, against his conviction for illegally possessing a gun and ammunition.
Dismissing his application for permission to appeal, Lord Chief Justice Lord Thomas ruled that there was nothing in the grounds he wished to argue which affected the safety of Nightingale's conviction.
Last July the former SAS sniper was sentenced to two years' military detention, suspended for 12 months, by a military court in Bulford, Wiltshire, after being convicted for the second time.
He was found guilty of having a 9mm Glock pistol and more than 300 rounds of ammunition in the bedroom of his shared Army house.
Former SAS sniper Danny Nightingale, from Crewe, Cheshire, has lost his latest battle against his conviction for illegally possessing a gun and ammunition.
Former SAS sniper Sergeant Danny Nightingale is to appeal against his conviction for illegally possessing a gun and ammunition, his lawyer has said.
Simon McKay said papers were lodged at the Court of Appeal yesterday against the two years military detention suspended for 12 months imposed on the 38-year-old special forces soldier by a military court last month.
The wife of former SAS sniper Danny Nightingale said the family would now take advice from counsel on whether to appeal his conviction for the possession of a pistol and ammunition.
Speaking outside court, Sally Nightingale said: "We're obviously very disappointed with the sentencing, yet we are pleased that Danny will be coming home with us tonight."
Judge advocate Jeff Blackett told Danny Nightingale, who wore his SAS uniform in the courtroom, that his stories about how the gun came to be in his room "lacked credibility".
But he said there were "exceptional circumstances" that allowed the court to suspend the sentence "because of your exceptional character".
The judge also said that "criticism of the prosecution and the Army is unmerited and totally without foundation".
We understand how difficult these proceedings have been for you and your family. However, you have brought much of that anguish upon yourself and your public assertions that you are scapegoat or the victim of some wider political agenda is absolute nonsense.
You are simply someone against whom there was a strong prima facie case of serious wrongdoing and, given the dangers to society caused by illegal firearms and their misuse, it was in the public interest to prosecute you.
You have now had a fair trial before a civilian judge and an independent and impartial board.
Former SAS sniper Sergeant Danny Nightingale has been sentenced to two years military detention today for the possession of a pistol and ammunition. The sentence has been suspended for 12 months.
Former SAS sniper Sergeant Danny Nightingale has arrived at the Military Court Centre in Bulford, Wiltshire to be sentenced for a second time for the possession of a pistol and ammunition.
Sergeant Nightingale had originally pleaded guilty to the two charges last year and was sentenced to 18 months' military detention.
The father of two, from Crewe, Cheshire, appealed against that sentence and it was reduced to 12 months' imprisonment, suspended for a year.
He then fought to overturn his convictions and won a fresh court martial, which found him guilty after four hours of deliberations.
"I never regret fighting it, no. No, not for one second," Sgt Nightingale said after being released on bail.
An SAS sniper who could be jailed after being convicted of possessing a pistol and more than 300 rounds of ammunition said he had no regrets in fighting the case.
Sergeant Danny Nightingale, 38, was found guilty of two charges of possessing a Glock 9mm and 338 rounds by a court martial board.
Sentencing was adjourned but Sgt Nightingale could now be sent to the Military Corrective Training Centre in Colchester, Essex.
Former SAS sniper Sergeant Danny Nightingale has said he will seek legal advice after being convicted for a second time of gun offences.Read the full story ›