The parents of terminally-ill baby Charlie Gard are preparing for another legal battle with doctors at the UK's most famous children's hospital.
Chris Gard and Connie Yates want a judge to rule that 11-month-old Charlie, who suffers from a rare genetic condition and has brain damage, should be allowed to undergo a therapy trial in the United States.
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.
The couple, who are in their 30s and come from Bedfont, west London, are scheduled to mount the latest stage of their legal fight at the High Court on Thursday.
Charlie's parents 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 in Strasbourg, France, to intervene.
The couple now want the High Court judge in London who made the initial ruling to carry out a fresh analysis of their case.
Mr Justice Francis, who in April ruled in favour of Great Ormond Street doctors and decided that Charlie should be allowed to ''die with dignity'', oversaw a preliminary hearing in the latest round of litigation on Monday.
He told the couple that he had already analysed the case at a trial and would not rake over old facts.
But he said he would consider any new evidence and scheduled another hearing in the Family Division of the High Court for Thursday.