Doctors have been told to continue providing life-support treatment to a terminally ill baby at the centre of a high-profile legal battle for another three weeks to give judges in the European Court of Human Rights time to analyse the case.
Chris Gard and Connie Yates want 10-month-old Charlie Gard, who suffers from a rare genetic condition and has brain damage, to undergo a therapy trial in the US.
Specialists at Great Ormond Street Hospital for Children in London, where Charlie is being cared for, say therapy proposed by a doctor in the US is experimental and will not help.
They say life support treatment should stop.
Charlie's parents hope judges in the European Court of Human Rights, in Strasbourg, France, will come to their aid after losing battles in the High Court, Court of Appeal and Supreme Court in London.
Their lawyers on Monday filed detailed legal arguments and Strasbourg judges say they will treat Charlie's case with the "utmost urgency".
Supreme Court justices in London say Great Ormond Street specialists should keep providing life-support treatment until midnight on July 10.
Three justices had analysed issues relating to continued treatment, pending a decision by European court judges, at a hearing in London early on Monday.
A European Court of Human Rights spokeswoman said the case would get "priority".
"In light of the exceptional circumstances of this case, the court has already accorded it priority and will treat the application with the utmost urgency," she added.
"It is anticipated that as soon as the responsible chamber of the court is in a position to consider the application made on behalf of Charlie Gard and his parents an expedited timetable for the determination of this application will be established."
A High Court judge in April ruled against a trip to America and in favour of Great Ormond Street doctors.
Mr Justice Francis concluded life support treatment should end and said Charlie should be allowed to die with dignity.
Three Court of Appeal judges upheld that ruling and three Supreme Court justices dismissed a further challenge by the couple.
Mr Justice Francis made a ruling after a trial in the Family Division of the High Court in London.
He heard that Charlie, who was born on August 4 last year, has a form of mitochondrial disease, a condition which causes progressive muscle weakness and brain damage.
Specialists in the US have offered a therapy called nucleoside.
Lady Hale, the Supreme Court's Deputy President, had headed the three strong panel of justices which considered issues surrounding Charlie's continued treatment.
She has outlined the justices' conclusions in a written ruling.
Lady Hale said justices had to consider whether to further "stay" Mr Justice Francis's decision to allow doctors to stop providing life support treatment.
She said Mr Justice Francis had decided what was in Charlie's best interests.
Charlie's parents had already been given time to mount challenges in the appeal court and Supreme Court and had exhausted legal options in the UK.
"It is hard to over-stress the difficulty which, in this desperately painful case in which the intensity of the parents' feelings is so entirely understandable, the prospect of yet a further stay places upon this court, upon the hospital and, of course overarchingly ... upon Charlie himself," said Lady Hale.
"Mr Justice Francis made his declarations on 11 April 2017.
"Since then there have been numerous successive stays of them.
"Every day since 11 April 2017 the stays have obliged the hospital to take a course which, as is now clear beyond doubt or challenge, is not in the best interests of Charlie.
"The hospital finds itself in an acutely difficult ethical dilemma."
She added: "We three members of this court find ourselves in a situation which, so far as we can recall, we have never previously experienced.
"By granting a stay, even of short duration, we would in some sense be complicit in directing a course of action which is contrary to Charlie's best interests."
But Lady Hale said Charlie's parents also had a right to ask the European court to consider the case and she said justices had decided that treatment should continue.
"With considerable hesitation we direct that the judge's declarations be further stayed for a period of three weeks, namely until midnight on 10/11 July 2017," she said.
"We respectfully urge our colleagues in the European Court of Human Rights to do everything in their power to address the proposed application by then.
"We consider at present that we would feel the gravest difficulty if asked to act yet further against Charlie's best interests by directing an even longer extension of the stay."