A couple who want to take their terminally ill baby son to the United States for treatment are waiting to see whether judges in the European Court of Human Rights will come to their aid.
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 America.
They have asked European Court judges in Strasbourg, France, to consider the case after exhausting all legal options in the UK.
Strasbourg judges are expected to make an announcement on Tuesday.
They have told doctors in London to continue providing life-support treatment to Charlie until midnight on Tuesday to give them time to examine papers filed by his parents' lawyers.
Specialists at Great Ormond Street Hospital in London, where Charlie is being cared for, say therapy proposed by a doctor in America is experimental and will not help.
They say life-support treatment should stop.
A High Court judge in April ruled against a trip to America and in favour of Great Ormond Street doctors.
Mr Justice Francis concluded that life support treatment should end and said Charlie should be allowed to die with dignity.
Three Court of Appeal judges upheld that ruling in May and three Supreme Court justices on Thursday dismissed a further challenge by the couple after a hearing in London.
Mr Justice Francis had made a ruling on April 11 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, had 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.
Charlie's parents, who are in their 30s and come from Bedfont, west London, have appealed for money on a GoFundMe page to cover doctors' bills in America.
They reached a £1.2 million target before the High Court trial.
People are continuing to donate and the fund has now topped £1.3 million.
Mr Justice Francis said Great Ormond Street doctors had considered the experimental treatment, but decided it would not help Charlie.
He said the case had never been ''about money''.
Lawyers representing Charlie's parents say parents should be free to make decisions about their children's treatment unless any proposed treatment poses a risk of significant harm.
Richard Gordon QC, who leads the couple's legal team, told the Supreme Court that the state was not ''entitled to cause a child's life to be extinguished''.
Supreme Court justices said Charlie's parents were devoted and said any judge was bound to be sympathetic.
But Lady Hale, who headed the panel of justices which considered the case, said parents were not entitled to insist on treatment which was not in their child's best interests.
She said Mr Justice Francis had done nothing wrong when reaching the conclusions he had reached.