John and Lizanne Malpas, who wed in 2006, have run the popular Sandwich Station at Lochranza on the Isle of Arran since 2017.
But now strict visa rules could see Lizanne, 37, forced to leave behind her husband and livelihood as soon as Friday.
The pair relocated to the idyllic isle in 2015 after working at a hotel together and travelling throughout Africa.
Lizanne's spousal visa expired last month but her renewal was refused by the Home Office because her business earnings were insufficient.
A written and online petition have since raised more than 16,000 signatures and 16,487 signatures respectively - considerably more than Arran's 5,000 resident population.
The couple registered the sandwich shop in February 2017 and started trading in May 2017.
However, Mr Malpas said the Home Office only took into account revenue from February 2017 to 2018 - their first year of trading - missing out on money made from 2018 to 2019.
Mr Malpas, 38, said: "We came over in 2015 and then decided to settle here.
"Lizanne went back to South Africa to apply for a visa and I had a lump sum of money left over from my parents dying and helped get her in through my savings.
"We then took up jobs before the Sandwich Station and I sunk all my money into that."
"It's in the process of doing really well.
"We didn't pay ourselves very much and we own the house we live in.
"Our lawyer tried to file an appeal under human rights section eight, right to family life, but they refused.
"We hadn't heard anything at all until June 19 when we got an email and a call from our lawyer to say our application had been refused and Lizanne wasn't liable to stay and said she would be deported and had to stop working immediately."
Last week Patricia Gibson, MP for North Ayrshire and Arran, spoke out on behalf of Mrs Malpas in the House of Commons.
During her speech, she called the move by the Home Office an "appalling decision".
She said: "I wish to raise a point of order on behalf of my constituent Lizanne Zietsman who is a wife, businesswoman, employer and valued and respected community member on the isle of Arran.
"She has been ordered to leave the UK by the 12th of July by the Home Office.
"I have taken this most urgent matter up with the immigration service and the immigration minister, and to further highlight this case I have tabled an early day motion and will present a petition to parliament to show the strength of feeling about this matter."
Their MP is due to present the written petition in parliament today (Tue).
Mr Malpas said: "Our MP has been massively helpful.
"Everybody's been helping as much as they can."
But despite the heartfelt well wishes of the Arran community, Mr Malpas said he has lost all hope in the immigration service.
He said: "It's been very unsettling and I have a complete lack of faith in the system.
"There's definitely a hostile environment.
"One of the real problems with the application is that we put in information about the financial situation and if they looked at a more recent part it would've been fine.
"Now they're wanting to split us up.
"It just feels like we've become victims of their immigration targets.
"We're hoping for the best but planning for the worst."
The Home Office has been approached for comment.