Identical twins Darcy and Omega Russell (12) should be looking forward to the holiday of a lifetime next year in Florida with their legal guardian, Heidi Lovley (29), a neighbour who took them in after their mother died from cancer.

But their hopes of a fun-filled break in the sun have had to be put on hold after they were refused passports because their late mum, Lianne, was born in Kuwait.

Now Miss Lovley is battling the Home Office to prove the girls have lived in the UK for 10 years, so they can be confirmed as UK citizens eligible for passports.

She has had to start digging out medical and school records to support the girls' claim – even though they were born in Peterborough.

Miss Lovley, a customer services worker for Thomas Cook, said the decision that the Jack Hunt School pupils were not automatically considered British citizens had come as a shock.

She said: "In my ignorance, I assumed that if you were born here, then you are a British citizen. But it isn't that simple.

"I'm not angry, but this is pure frustration and I find it really ridiculous. We were hoping to go abroad over the half-term in October, and to Florida later.

"But we have had to put back Florida until October next year because it can take seven months from sending all the information in, and we wanted to allow extra time for anything else that might crop up."

The twins, of Brookfurlong, Ravensthorpe, lost their 42-year-old mother to cancer two years ago, and Miss Lovley, a family friend who had lived in the same road since 2001, became their legal guardian with the backing of social services.

It was after applying for passports for the girls, that she received a letter from the Identity and Passport Service telling her they first needed to gain British citizenship.

The law says that even when someone is born in the UK, to be entitled to citizenship their father or mother must also be a British citizen or be settled in this country.

The girls met the birth qualification, but their citizenship is in question because Lianne was born in Kuwait while her father was working abroad, casting doubt on her own nationality status. The issue does not seem to have been resolved while she was alive.