After months of legal back-and-forth, the family of Archie Battersbee saw their last hope extinguished on Monday as a court ruled his life support should be switched off within hours.
They had pinned their hopes on an intervention from a United Nations committee which has power to raise complaints over the treatment of disabled people.
But the most senior judge in the family courts said it was "not part of the law of the United Kingdom" and no more than an "unincorporated international treaty".
So why did the 12-year-old's family believe that the UN route was a lifeline?
Why did Archie's family apply to the UN?
Polly Morgan, associate professor of law at University of East Anglia, said it had always been a long shot to apply to the United Nations, due to the lack of power it has in UK courts.
Speaking before judges had made their decision, Prof Morgan said: "It's very unlikely to change the ultimate outcome, because the decisions made by the UN committee are not binding on our courts.
"They cannot be compelled to do what the recommendation is, because that's all it is.
"It would also involve the courts making an order which they do not believe is in the best interests of Archie, as they believe taking Archie off life support is in his best interests."
On Monday's hearing, the head of the family division at the High Court, Sir Andrew McFarlane, concluded a short stay could be granted until 12pm on Tuesday.
He added Archie's parents could "take stock and decide if they want to make any further application to the Supreme Court".
What is the UN Convention and what powers does it have?
The UN Convention on the Rights of Persons with Disabilities is an international human rights treaty signed between countries.
Professor Morgan said it was "very unusual" for individuals to go to the convention with an issue, as the European Court on Human Rights usually deals with such issues.
The ECHR is part of the UK's domestic law, but the UN Convention is not, meaning Archie's case was "new territory", Prof Morgan explained.
This means the UN Convention cannot overrule a UK court decision.
When Archie's family announced they would be taking their case to the UN Convention rather than ECHR, they said it was because the ECHR has "a track record" of rejecting applications from parents in end-of-life cases such as Archie's.
What led to Archie's family's UN request?
The 12-year-old from Southend, Essex, has been unconscious since being found with a ligature around his neck in April and was due to have his life support ended at 2pm on Monday, before the short stay until Tuesday was granted.
Doctors treating Archie at the Royal London Hospital in Whitechapel, east London, believe he is "brain-stem dead" and said continued life support is not in his best interest.
A High Court judge, Mrs Justice Arbuthnot, considered the case and concluded, after an earlier hearing, that Archie was dead.
But Court of Appeal judges upheld a challenge by Archie’s parents against decisions taken by Mrs Justice Arbuthnot and said the evidence should be reviewed.
The case was referred back the High Court, where Mr Justice Hayden ruled that life support could be lawfully withdrawn and after a second appeal from the family, Court of Appeal judges backed Mr Justice Hayden's assessment.
That led Archie's family to seek other avenues to overturn the decision, leading them raise the issue with the United Nations.
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