"Hope" (Picture courtesy of Hope's family)

"Ariana Grande is an actress and a singer," 10-year-old Hope says excitedly. "But I'd like to be an actress and a nurse. I'll be a nurse part-time, then perform in the evenings."

Unlike most starry-eyed preteens, Hope will struggle to realise either part of her dream. She was born in Britain, speaks only English and has lived her whole life here, but unless her impoverished single mother can raise a £936 registration fee, she will be denied her right to register as a citizen.

She will not be able attend university, or train and work as a nurse. In fact, she will not even be able to access basic NHS services without paying.

After a decade spent living in the UK, children are legally entitled to become British citizens, even if their parents are here illegally or on limited visas. That means access to the NHS, universities and legal work: it means freedom of movement, freedom from the fear of deportation.

But their parents can come up with nearly £1,000, already-impoverished children like Hope to a precarious, fearful existence, with a temporary and insecure Leave to Remain (LTR) status or no legal status at all.

While Hope hones an Akon dance routine, her mum Tabitha, 37, draws me aside: she does not want her daughter to know how worried she is. "We don't have that kind of money," she says simply. "At the moment, I can't access any public funds, Jobseekers' allowance, tax credits… My children don't have child benefits. They don't have anything."

"But Hope would have a lot to give to society. She does very well at school, she participates in everything, and she's very caring."

The fee was hiked by 25 percent last year and comes backed by a host of harsh legislation further distancing the vulnerable from their rights. By the government's own admission, it's three times higher than the actual cost of processing an application.

Immigration solicitor Solange Valdez runs the Project for the Registration of Children as British Citizens (PRCBC). "It's daylight robbery," she tells VICE. "You cannot charge someone who has a statutory right to British citizenship. But slowly, silently, those rights are being chipped away."

Children discovering they are not and cannot be citizens like their schoolmates suffer distress, shame and anger. One 18-year-old, whose dreams of studying politics at university were shattered after he failed to gain citizenship, told PRCBC: "It became apparent that if you weren't British… your life pretty much ended."

Tabitha says she can already see Hope suffering: "She's a sensitive child and she's already asking me questions – 'Why do they have to decide [about] my life?'"

There can also be knock-on effects for children's families. Tabitha's status is under review by the Home Office. She can't gain citizenship, and may be deported. "If I'm not deported, I can work to contribute to the community and support my children, to help others and help myself," she says.

"They're treating British-born black kids as migrants – it's disgraceful."

Unable to work legally, Tabitha and her three children were recently evicted from a flat by Haringey Council. "They said my children were not in need," she says. "But we could have been in the street." Someone who knew Tabitha through volunteer work gave up their own spare room as temporary accommodation, and the family has since been rehoused in Islington.

Tabitha's own case will be bolstered if Hope becomes a citizen. Conversely, in circumstances where a child aged ten to 18 cannot afford a citizenship application and a parent is deported, Solange says "children might be returned to [a foreign country], though the right by Parliament to citizenship is retained".

Hope's case is far from unique. There are an estimated 120,000 undocumented children in the UK, around half of whom were born in the UK. But it is impossible to know how many children turn 18 without raising the funds to exercise the rights they have to stay in the UK, including rights to citizenship.

A Home Office spokesperson told VICE: "UK Visas and Immigration fees are based on an estimated cost of dealing with an individual application plus a contribution to the costs of operating the overall border, immigration and citizenship system."

The Home Office has previously said fees are so high because "the benefits of British Citizenship are considered to be amongst the most valuable offered by the Home Office", and so children are charged on the understanding they will "profit" from British citizenship later in life.

But like every other British citizen, they will be paying taxes all their working life to fund these services. "These benefits are not for the Home Office to sell; the right to them has been given by Parliament," says Solange. The 3,000-plus children each year who have their applications denied are not refunded a penny.

It is perhaps more telling that Gordon Brown's security advisor told the House of Lords a fee waiver "may encourage migrants to remain unlawfully in the UK and submit speculative claims". These fees function as a deterrent.

Tabitha points out this can't apply to children like Hope: "These children are born here, they're not coming here." Solange agrees: "They're treating [British-born] black kids as migrants – it's disgraceful."

Children in care find it particularly difficult to gain citizenship. Cash-strapped councils are often more ready to seek precarious, limited Leave to Remain status, for which a fee waiver is available, and unwilling to cough up £936 for citizenship. Looked-after children, already exceptionally vulnerable, are left with a lesser status and insecure future as they enter adulthood.

Asked why she wants to be a nurse, Hope says with a grin: "Mary Seacole is bae." It seems needlessly cruel that this excitable schoolgirl, who clearly knows her British history, may be denied the chance to emulate the Jamaican-born nurse who tended to British soldiers in the Crimean war.

"Our food is British food," says Tabitha, over a slice of homemade pizza prepared by Hope. "We know everything about Britain; we know the values and the culture – we are British already… we just need the official paperwork."