A single mother who wants doctors to keep treating her brain-damaged daughter is preparing to take her case to the Supreme Court, according to a campaign group.
Paula Parfitt believes five-year-old Pippa Knight should leave hospital and wants specialists to carry out a home-care trial.
But doctors treating Pippa, who is in a vegetative state at the Evelina Children's Hospital in London, disagree and think life-support treatment should end.
Ms Parfitt, 41, of Strood, Kent, has previously lost legal fights in the High Court and Court of Appeal.
The Society for the Protection of Unborn Children has paid for lawyers to represent her, and officials from the campaign group say they will fund a Supreme Court challenge.
They claim lawyers are preparing an application to the UK's highest court.
High Court judge Mr Justice Poole earlier this year ruled against Ms Parfitt.
He decided treatment could lawfully end and said Pippa should be allowed to die.
In February, Ms Parfitt asked Court of Appeal judges to overturn Mr Justice Poole's decision.
Lady Justice King, Lord Justice Baker and Lady Justice Elisabeth Laing last Friday upheld Mr Justice Poole's decision.
After losing her Court of Appeal fight, Ms Parfitt vowed to continue her legal battle.
She said: "I am once again devastated as a result of the judgment of the Court of Appeal today, to uphold the decision that it is not in Pippa's best interests to have a two week trial of portable ventilation to find out whether she could come home.
"I find it inexplicable that the court and (hospital) trust will not allow Pippa to trial portable ventilation for two weeks to see if she can return home when the hospital allows Pippa to go outside for long periods on portable ventilation with no issue."
She added: "I will be seeking permission to appeal to the Supreme Court. I want Pippa to have every possible chance to come home and be with her family."
Mr Justice Poole had heard evidence at a trial in the Family Division of the High Court in London last December, and delivered a ruling in January.
The judge, who heard that Pippa's father was dead, described the case as "heart-rending".
Pippa was born in April 2015 and initially developed normally, but in December 2016 she became unwell and began to suffer seizures, the judge heard.
Doctors diagnosed acute necrotising encephalopathy.