A High Court judge has ruled that a seven-year-old boy can receive radiotherapy for a cancerous brain tumour against the wishes of his mother - whose judgment, he said, had "gone awry".
Mr Justice Bodey dismissed Sally Roberts' attempt to prevent radiotherapy treatment being given to her son, Neon - and expressed concern over her decision-making regarding the child's welfare.
Ms Roberts, who had earlier failed in a similar legal bid to prevent surgeons performing a follow-up operation on Neon, said she feared that radiotherapy would cause long-term harm.
Mr Justice Bodey, who had been told by doctors that Neon could die within months without radiotherapy treatment, said he sympathised with the "nightmare" confronting Ms Roberts. But he said he was worried that she had not grasped the seriousness of Neon's situation.
"The mother has been through a terrible time. This sort of thing is every parent's nightmare and I have sympathy for her," said the judge, following a hearing in the Family Division of the High Court in London. "But I am worried that her judgment has gone awry on the question of the seriousness of the threat which Neon faces."
He said the operation Ms Roberts had opposed was life-saving and added: "I have become concerned about the mother's attitude to Neon's welfare generally."
The judge ruled that radiotherapy sessions could start and said Neon should live with his father, Ben - who is separated from Ms Roberts - for the duration of his treatment. And he said that, in future, doctors would need only Mr Roberts' consent when making decisions about Neon's cancer treatment.
He said it was important that doctors were not hampered by a "stalemate" if parents took differing views.
Ms Roberts, 37, a New Zealander who lives in Brighton, East Sussex, said after the hearing that she was "not allowed" to comment.
Mr Roberts, who lives in London and had consented to radiotherapy treatment, was said to be "relieved".