An American specialist who has offered to treat Charlie Gard is preparing to fly to London to examine the terminally-ill baby for the first time.
Michio Hirano is scheduled to visit Great Ormond Street Hospital in London, where 11-month-old Charlie is being cared for, over two days next week.
Dr Hirano is due to arrive at the hospital on Monday and discuss Charlie's condition with doctors treating the boy and with independent specialists.
Detail of the plan emerged on Friday during the latest round of a legal fight between Great Ormond Street bosses and Charlie's parents.
Chris Gard and Connie Yates want the judge to rule that their 11-month-old son, who suffers from a rare genetic condition and has brain damage, should be allowed to undergo a therapy trial overseen by Dr Hirano in New York.
Specialists at Great Ormond Street say the therapy is experimental and will not help.
They say life support treatment should stop.
Charlie's parents, who are in their 30s and come from Bedfont, west London, have already lost battles in the High Court, Court of Appeal and Supreme Court in London.
They have also failed to persuade European Court of Human Rights judges to intervene.
But the couple say there is new evidence and want Mr Justice Francis to carry out a fresh analysis of their case.
In April, the judge ruled in favour of Great Ormond Street and said Charlie should be allowed to die with dignity.
Mr Justice Francis has considered their claims at preliminary hearings in the Family Division of the High Court in London.
He is due to stage further hearings later this month following next week's gathering of specialists.
Dr Hirano gave evidence, via a link from New York, at a hearing on Thursday.
The judge said he wanted to hear what Dr Hirano believed had changed since he gave his ruling in April.
Dr Hirano said he had clinical data which was not available in April and he still believed that the therapy was ''worth trying''.
The doctor estimated that there could be a 10% chance of improvement in muscle strength and a ''small but significant'' improvement in brain function.
He told the judge that he had never seen or examined Charlie.
Mr Justice Francis suggested that a visit to Great Ormond Street and discussions with specialists treating Charlie would be a good idea.
The judge said Charlie's mother could attend a specialists' meeting at Great Ormond Street next week.
Lawyers representing Great Ormond Street initially said neither of Charlie's parents should feature in a meeting of specialists next week.
They said the aim of the meeting was to allow medical experts to have a detailed scientific discussion.
Lawyers representing Charlie's parents objected to the meeting being staged in the absence of both parents.
Both sides agreed, after discussions, that Charlie's mother could take part.
Speaking on behalf of Charlie's family, spokesman Alasdair Seton-Marsden said outside court: "Today GOSH tried to block the parents of Charlie Gard from attending a meeting about their own child.
"After protracted legal discussions the court decided mum could attend that meeting.
"GOSH seem to want to exclude the parents at every stage.
"We are delighted that Charlie's mother, Connie, will be present at the meeting that Prof Michio Hirano, the world's leading expert on Charlie's condition, will attend.
"The professor will be flying in from Columbia University Medical Centre, New York, for a meeting this Monday to see Charlie.
"This is excellent news."
Mr Seton-Marsden added: "We have heard reports that threats have been made against the judiciary and medical staff at GOSH.
"In no possible circumstances whatsoever does any member of Charlie's family or any of Charlie's true supporters condone any such action."