The mother of a 12-year-old boy who suffered a “catastrophic” brain injury three months ago says she will keep fighting despite losing the latest round of a battle to continue his life-support treatment.

Doctors say continued treatment is not in Archie Battersbee’s best interests and should end.

Archie’s parents, Hollie Dance and Paul Battersbee, from Southend in Essex, disagree, and say his heart is still beating.

A judge, who reviewed evidence at a hearing in the Family Division of the High Court earlier this week, concluded on Friday that ending treatment was in Archie’s best interests.

Mr Justice Hayden described what had happened to Archie as a “tragedy of immeasurable dimensions”.

But he said medical evidence was “compelling and unanimous”, and painted a “bleak” picture.

Ms Dance said she now wanted to ask Court of Appeal judges to overturn Mr Justice Hayden’s ruling.

“Archie would want us to keep on fighting,” she said.

“And we will keep on fighting. We will appeal.”

Mr Battersbee said: “There have been too many battles in too short a space of time.

“He needs more time. We’ll try to appeal. Who knows?”

Miss Dance said Mr Justice Hayden’s ruling was a “crushing blow”.

“With all due respect to Mr Justice Hayden, it is not in Archie’s best interests to die,” she added, outside court.

“The planned removal of the ventilator is definitely the worst thing that may happen from my point of view. I cannot see how this is in any way dignified.

“We disagree with the idea of dignity in death. Enforcing it on us and hastening his death for that purpose is profoundly cruel.

“It is for God to decide what should happen to Archie, including if, when and how he should die.

“As long as Archie is fighting for his life, I cannot betray him.

“Until Archie gives up, I won’t give up.

“I am living every parent’s worst nightmare.

She added: “There must be change in the NHS and in the court system before another family has to go through what we have.

“We will be appealing this ruling and we ask for your prayers and support.”

Another High Court judge, Mrs Justice Arbuthnot, had earlier concluded that Archie was dead, but Court of Appeal judges upheld a challenge, made by Archie’s parents, to decisions taken in that hearing and said evidence should be reviewed.

Doctors treating Archie at the Royal London Hospital in Whitechapel, east London, have told judges they think he is “brain-stem dead” and say continued life support treatment is not in his best interests.

Lawyers representing the Royal London Hospital’s governing trust, Barts Health NHS Trust, have asked for decisions about what medical moves are in Archie’s best interests.

Ms Dance has told of how she found Archie unconscious with a ligature over his head on April 7 and thinks he might have been taking part in an online challenge.

He has not regained consciousness.

Mr Justice Hayden said  evidence showed that Archie had suffered a “significant injury” to “multiple areas” of his brain and had not “regained awareness at any time”.

“Archie’s mother described him as a fighter and I have no doubt he was,” said Mr Justice Hayden.

“But the fight, if it can properly be characterised as such, is no longer in Archie’s control.

“The damage to his brain has deprived him of any bodily autonomy.

“Eventually Archie’s organs will fail and ultimately his heart will stop.”

Mr Justice Hayden said the reality of Archie’s case was “terrible”.

He said: “The medical evidence finds that for Archie improvement is not possible.

“There is unfortunately no treatment possible to reverse the damage that has been caused to Archie’s brain.

“There can be no hope at all of recovery.”

The judge said he had reached his conclusions with “profound regret”.

Ms Dance, Mr Battersbee and other members of Archie’s family were in court to hear the judge outline his conclusions.