Baby Indi Gregory's family have lost their recent attempt to prevent the removal of her life support.The eight-month-old is suffering from an "irreversible" mitochondrial disease.
Despite the family's wish to transfer her to a Rome hospital, the courts sided with the medical team at Nottingham's Queen's Medical Centre, who argued it was in her "best interests" to pass away.
Earlier this week, the Bambino Gesù Paediatric Hospital in Rome offered fully funded treatment, prompting Italy to grant her citizenship and seek jurisdiction under Article 9.2 of the Hague Convention in the UK High Court.
But on Friday, UK judges rejected the Italian intervention, ruling it "wholly misconceived" and "not in the spirit of the convention".
The judges, including Lord Justice Peter Jackson, Lady Justice Eleanor King, and Lord Justice Andrew Moylan, ordered the immediate removal of Indi's life support and denied permission to appeal an earlier decision preventing the removal of life support at home.
Indi's parents expressed disgust at the one-sided decision, insisting on pursuing the best treatment for their daughter.
"Claire and I have always wanted what is in Indi's best interests. She has human rights and we wanted her to have the best treatment possible," Mr Gregory said.
"If the UK did not want to fund it, why can she not go to Italy and receive the treatment and care which the amazing Italian Prime Minister and government has offered.
"This feels like the latest kick in the teeth, and we will not give up fighting for our daughter's chance to live until the end."
The family is being supported by the Christian Legal Centre. Its CEO, Andrea Williams, commented: "Life is the most precious gift we have.
"There is a hospital prepared to care for Indi in Rome. Indi's parents desire to give her every chance they can. Why would anyone try to stop this happening for them and for her?
"To continue to deny them this opportunity is unimaginable."