A 67-year-old British woman who planned to return to Britain with her 80-year-old French husband after 30 years in France has told how Home Office delays have left them waiting almost a year for the Brexit paperwork they need to set foot in the country.

Carmel and her husband, Louis, who asked that their real names not be used, sold their house last year and packed up all their belongings having read that it would take 15 days to get a family permit.

They applied for the paperwork on 22 April and but have been in limbo for 10 months, camping out with their children and unable to get on with their lives.

“We packed everything up. We sold the house. And it’s just non-communication from the Home Office,” said Carmel “My husband went through a phase of being very depressed about the whole thing. He said: ‘What are the Home Office waiting for, for me to die?’ sort of thing.

“I think we’ve got to the point of disbelief. We are in this situation, but how are we in this situation?”

Carmel said they had had a very happy 30 years in France but wanted to return home. “We feel like we are a victim of Brexit and there is nothing we can do about it. We are just waiting. We can’t get on with our lives,” she said.

Carmel is one of thousands of British citizens living in Europe furious that their rights have been compromised because of Brexit despite government promises to the contrary.

The campaign group British in Europe has written to four secretaries of state including Liz Truss, the foreign secretary, and Priti Patel, the home secretary, begging them to deliver on Conservative party promises that British citizens in the EU would not face an erosion of rights because of Brexit.

It has urged the four cabinet members, who also include Thérèse Coffey, the work and pensions secretary, and Nadhim Zahawi, the education secretary, not to forget the 1.2 million British citizens in Europe and warning them of four potential risks they face because of Brexit.

These include ongoing issues for British citizens trying to return home, and a call for them to extend a 29 March deadline for applications for those non-UK spouses to apply for settled status.

It also wants them to answer a request to issue a “clear statement that those family members who are entitled to enter the UK on a visitor permit will be able to do so in order to move physically to the UK” to make the application to remain under the EU settlement scheme.

It is thought there are thousands of British nationals waiting for permits to make the move home permanent, but the Home Office has declined freedom of information requests and parliamentary questions from the former Brexit select committee chair Hilary Benn for data.

British in Europe is closing after six years at the Brexit frontline because it has been unable to secure funds. In its valedictory letter it tells the cabinet members that support for Britons is needed more than ever.

It has urged Truss and her colleagues to scrap the decision to cancel dedicated funding in embassies and consular posts to support British citizens in the EU and the European Economic Area, arguing that they need dedicated officers in post until at least the end of 2022.

It has also urged them to implement the seven-year grace period on home fees and student finance for children of British people living in Europe and to ensure that potential changes to the personal independence payments do not affect recipients in the EU.

The letter was sent before a meeting on Monday of UK and EU officials sitting on a Brexit specialised committee on citizens’ rights.

A home office spokesperson declined to give a reason for a 10-month delay. They referred to “complexity”, which many applicants for family permits have complained was a “standard” response to questions on the whereabouts of their applications.

“Applications for EU settlement scheme (EUSS) family permits are decided as soon as possible, but waiting times can vary depending on the volume of applications received and the complexity of the case being considered. As a result, customers may experience a longer wait than usual for their decision on their EUSS family permit applications,” the spokesperson said.