Soldiers, welfare organisations and senior politicians are calling on the Home Office not to deport the wife of a serving British soldier.
The couple met while L/Cpl Crozier was stationed in Canada
Samantha Crozier, who is a Canadian national, has been told that she must leave Britain when her temporary visa runs out in April.
She has been told she will have to go back to her home country if she wants to re-apply for citizenship.
The government says the rules exist to prevent the immigration system from abuse.
'Cruel and ungrateful'
Samantha Crozier met British serviceman L/Cpl Andrew Douglas Crozier six years ago, while he was stationed in Canada.
They married, and four years ago moved to Germany, while he was posted with the Royal Electrical and Mechanical Engineers.
In that time they had two children, Ethan, two, and one-year-old Caleb, who were both granted full British passports.
When the family learned that Andrew was to be moved to the UK, Samantha applied for a temporary visa.
The family arrived in Britain several months later, and she then applied for a full citizenship.
Three weeks ago she was informed that her application had been rejected.
"I got a letter through saying I had been declined for the simple reason of I applied while I already had a stamp saying I'm allowed to be in the country for six months," she said.
"I'm supposed to apply when I'm out of the country."
As the family lived in Germany before, there is a chance she could apply for British Citizenship from there.
If that doesn't work, she faces being sent back to Canada to apply again from there, a process which could take up to a year.
She is terrified about having to leave her two young boys without a carer while her husband is at work, and about having to cope financially on her own in Canada.
The Crozier family has a large campaign group supporting Samantha's bid to remain in the UK.
The Soldiers, Sailors, Airmen and Families Association (SSAFA) are providing financial and administrative support to the family while they go through this process.
There is a Facebook group with more than a thousand members, and its campaigners are calling for the government to allow her to apply for full citizenship while she is still in the UK.
Lib Dem Defence spokesperson Nick Harvey also sent a statement of support to Radio 5 Live.
Mrs Crozier says her husband's sacrifices should be considered
"Like all Armed Forces families, the Croziers have made huge sacrifices in the service of this country.
"For the government to claim that they have no right to be here is cruel and ungrateful in the extreme. We have a duty to ensure the welfare of this family.
"That is why I'm campaigning for a written military covenant to ensure that the government faces up to its duty of care."
Conservative MP Patrick Mercer believes that this issue is at the very heart of the covenant.
"Soldiers and their families deserve to be treated as an exception in these types of circumstances because of the extreme and unique risks that soldiers take on a day-to-day basis," he said.
The Ministry of Defence said in a statement that the rules for naturalisation are the responsibility of the Home Office.
The Home Office also sent a statement, which read: "Overseas nationals wishing to come to the UK on the basis of marriage should apply for entry clearance from abroad.
'Rules are rules'
"They will be given leave to enter the UK for two years, after which they can apply for settlement.
Despite the uncertainty over her future, Samantha is aware that the officials are only following their guidelines.
"I believe that rules are rules," she said.
"But at the end of the day I am an army wife.
"I don't think I'm special, but I also do think my husband lays his life down for this country, and I should get something back because of that."
If you are a Facebook member and would like to join the Crozier's campaign, sign in and search for Operation Keep Sami in U.K.