An ex-marine and serving bodyguard to the Queen has been left "angry and frustrated" after his French wife of 24 years was left fearing for her future right to stay in the UK.

Simon Milne MBE, 58, has served in Northern Ireland and Bosnia and is one of 27 Gentlemen at Arms who guard the Queen on royal occasions.

His wife Francoise, 50, applied for a permanent residency card after the Government "failed to clarify" the future rights of EU nationals living in the UK.

Ms Milne, who has three children with her husband, said her application was refused in October as she could not prove she was "self-sufficient", adding she has been left "scared and confused" about the future.

The couple's MP, the SNP's Deidre Brock (Edinburgh North and Leith), has written to ministers and raised their case in a Commons debate last week.

Mr Milne, who is chief executive of the Royal Botanic Garden Edinburgh, said he finds the decision "extraordinary".

He said: "With the uncertainty around Brexit at the moment my wife decided to apply for permanent residency.

"She has supported me through my career with the Royal Marines and now in my current role.

"I am flabbergasted with this decision, I am angry and frustrated. I can only hope that it is an unintended oversight."

Ms Milne, who lives in Edinburgh, told the Press Association that her "world has been shattered" by the Brexit vote.

She said: "It felt like I had been cut in half when the vote came back yes, my children were crying.

"I never felt I needed to claim dual nationality before, I could move about freely and work freely, now it feels like a lot of freedom has gone."

Ms Milne said she was refused a residency card because she could not prove she was "self-sufficient".

She said: "I do a little bit of upholstery, I never make enough to support myself and rely on my husband.

"They will not take into account that I am married to a British man, that is irrelevant, it's hard to believe.

"I don't know what will happen after 2019, I don't know if there will be time limits on how long I can stay in the country, if I want to leave to see my parents in France I don't know what the rules will be on coming back.

"I have participated in British society, I have raised three intelligent lovely children, I have voted, I have worked, I am, I have been a citizen."

Ms Brock said: "The Government says EU nationals shouldn't worry, then refuses residency to long-term citizens like Francoise.

"What an appalling way to treat people, making them feel unwelcome in their own homes.

"The Government's inertia on EU citizens' rights is not acceptable. We can't keep messing with people's lives, we need certainty now."

Speaking in the Commons last week, Home Office minister Brandon Lewis reiterated an agreement with the EU on citizens' rights is "within touching distance".

He said: "We will be working hard in the coming days and weeks to finalise this chapter of the withdrawal agreement and deliver our shared objective of providing swift assurance to EU citizens in the UK and UK nationals in the EU."

A residence card is issued by the Home Office and allows people to stay in the UK for a time-limited period but the cards will be not valid after the UK leaves the EU.

A new scheme will be available for EU citizens and their family members to apply to stay in the UK after it leaves the EU, according to the Government.

A Home Office spokesman said: "We are absolutely clear that the rights of EU nationals living in the UK remain unchanged.

"As the Prime Minister made clear in her open letter to EU citizens on 19 October, EU citizens who have made their lives in the UK have made a huge contribution to our country and we want them and their families to stay.

"Work is well under way to build a new application system for settled status from scratch, with new processes, technology, rules and support for applicants. The administrative process will be simple and streamlined, minimising the administrative burden on individuals."