A British court will hear an appeal later on Wednesday in the case of a gravely ill, 23-month-old boy whose case has attracted international attention, including from Pope Francis.
Alfie Evans has a rare, degenerative disease and has been in a semi-vegetative state for more than a year.
Medical experts in Britain agree that more treatment would be futile but his parents want to take him to the Vatican's Bambino Gesu children's hospital in Rome which has offered to care for him.
The case has provoked strong feeling over whether judges, doctors or parents have the right to decide on a child's life.
Following a court ruling on Monday, the child's life-support equipment was switched off but he has confounded expectations by continuing to breathe unaided.
On Tuesday, the High Court refused to allow his parents to take him to Rome and the Appeal Court on Wednesday will hear their appeal against that decision.
Alfie's parents Tom Evans and Kate James say they should have the right to decide what is best for the child.
"I'm not giving up because Alfie is breathing away, he's not suffering, he's not struggling, he's been given no (...) drugs, he's fighting," the boy's father told reporters.
Alfie has been in Alder Hey children's hospital in Liverpool since December 2016.
"We feel it is important for the public to know that decisions to withhold or withdraw treatment from a child are not made lightly," Alder Hey said in a statement on Tuesday.
The case has stirred up strong emotions, especially among a crowd of supporters calling themselves "Alfie's Army" camped outside the hospital.
Pope Francis has backed the child's parents in their attempts to get treatment in Rome. "I renew my appeal that the suffering of his parents may be heard and that their desire to seek new forms of treatment may be granted," he Tweeted on Monday.
Polish President Andrzej Duda has also lent his support, saying in a Tweet: "Alfie Evans must be saved! His brave little body has proved again that the miracle of life can be stronger than death."