There will be debate in the Commons later about the SAS sergeant jailed for possessing a gun.
Sergeant Danny Nightingale, a father-of-two who has served in Iraq and Afghanistan, was sentenced to 18 months in military detention by a court martial after he admitted having the 9mm pistol.
The gun, which was a gift from Iraqi soldiers he had been training, had been packed up and returned to him by colleagues in Iraq, after he had to leave the country in a hurry to help organise the funeral of two friends killed in action.
Sgt Nightingale, who also pleaded guilty to illegally possessing ammunition, suffers medical problems which affect his memory and said he did not remember having the weapon.
His wife Sally, who saw her husband for the first time in two weeks at the weekend, told Sky News: "We think Danny is the victim of a failure in the system and that he's been made an example of.
"I don't know how easy it's going to be to overturn this (the sentence). I'm not a lawyer myself and my understanding of the legal system is minimal.
"But I'm hoping that with the pressure and the support from the public and with the MPs on our side, we can get this overturned as quickly as possible and get Danny back home to his family."
Asked how her husband was coping at the Military Corrective Training Centre in Colchester, Essex, Mrs Nightingale said: "Danny's an outdoor person; he never sits still and it's very hard for him to be in there. But with all the support behind him, that will see him through."
Earlier, she said: "He has received letters from members of the public and... he is genuinely humbled."
The case is be debated by MPs after Mrs Nightingale wrote to David Cameron urging him to intervene.
Four special forces veterans, including the former commanding officer of the SAS, have also written an open letter to the Prime Minister, claiming Sgt Nightingale was "the victim of a monstrous miscarriage of justice".
His solicitor Simon McKay said he would be lodging an appeal against the detention on the grounds his client only pleaded guilty after being told he might otherwise be jailed for five years.
"That guilty plea is not a true reflection of how he feels about this case," Mr McKay told Sky News.
"He has always maintained that he wasn't legally guilty of possession of this firearm," he added.