European judges on Wednesday refused to issue an emergency ruling on maintaining life support for a British boy at his parents' request, as they fight a desperate legal battle to keep him alive against the advice of medics.

Archie Battersbee's life support at the Royal London Hospital was due to end at 11:00 am (10:00 GMT) on Wednesday.

But the 12-year-old's parents had sought a last-ditch ruling from the European Court of Human Rights (ECHR) to keep him alive. The ECHR said in a statement, however, that "the Court today decided not to issue the interim measure sought."

Archie's mother, Hollie Dance, condemned this "heart-breaking development" in a statement, while vowing, "We will fight to the end for Archie's right to live."

"We've now got to fight to see whether we can get him out of here to have a dignified passing at a hospice, it's just unfair," she told reporters outside the hospital.

The governing trust of the Royal London Hospital where Archie is being treated had said earlier it would not make any changes to Archie's care "until the outstanding legal issues are resolved."

Archie's mother found her son unconscious at home in April with signs he had placed a ligature over his head, possibly after taking part in an online asphyxiation challenge.

His parents want to take Archie abroad for treatment. 

"If this country can't treat him or is not willing to treat him, where's the harm in allowing him to go to another country?" Dance told reporters outside the hospital before the ECHR released its statement.

"I will continue to fight right until the bitter end."

UK courts ruled that ending life-preserving treatment for Archie was in his best interests as doctors believe he is brain-stem dead.

Archie is currently being kept alive through a series of medical interventions, including ventilation and drug treatments.

Archie had been due to have his life support ended Monday afternoon after his parents failed in a domestic legal bid to halt the move.

But the Court of Appeal granted them a hearing on Monday after the government urged judges to consider his parents' application to the UN Committee on the Rights of Persons with Disabilities.

The UN committee had asked for treatment to continue while it considered the case.

The appeal judges ruled that the UN request was not enforceable and refused permission to appeal to the Supreme Court, but granted a delay until Tuesday. Instead, his parents filed an application directly with the Supreme Court to consider the UN application.

Tuesday's deadline came and went as the top court looked at the case.

The Supreme Court judges said they had "great sympathy" with Archie's parents, but rejected their appeal saying there was "no prospect of any meaningful recovery."

The hospital's planned withdrawal of treatment was again extended after the ECHR bid was filed.