The parents of Archie Battersbee, 12, with brain damage, have been granted leave to appeal a court ruling that his life support should be stopped.
A judge last week decided that Archie was dead but the case must now be considered by the Court of Appeal.
Archie suffered brain damage after his mother found him unconscious at their home in Southend, Essex on April 7. He has not regained consciousness since.
It is believed that he may have participated in an online challenge.
Doctors believe he is ‘brain stem dead’ and should be taken off a ventilator at the Royal London Hospital.
However, his parents want the treatment to continue and say his heart is still beating and he shook his mother’s hand.
At the High Court today, their solicitor, Edward Devereux QC, said the evidence must show beyond a reasonable doubt that Archie is dead, rather than using a balance of probabilities test.
He also said the judge failed to consider the religious views of Archie and his family.
Mr. Devereux set out a number of other grounds of appeal, but eight of the nine were dismissed as without merit.
These included that the court erred in extending the common law definition of death to include brainstem death and that its best interests analysis was flawed.
Lawyers representing the Royal London Hospital’s governing trust, Barts Health NHS Trust, asked Judge Ms Arbuthnot to decide what was in the boy’s best interests.
The legal fight will now continue after she gave Archie’s parents, Hollie Dance and Paul Battersbee, leave to appeal and said the standard of proof issue was a ‘compelling reason’ for which the higher court should consider the case.
Archie’s parents are supported by the Christian Legal Center.
Andrea Williams, its chief executive, said: “A decision that death can be declared on a balance of probabilities sets a troubling precedent for our society and must be appealed.
“This case is the first of its kind in an English court and has raised significant moral, legal and medical questions about when someone died.
“Archie’s parents believe that the time and manner of his death should be determined by God and claim the right to pray for a miracle until it happens. This belief must be respected.”