The father of tragic "right to life" baby RB today withdrew his opposition to a High Court plea by doctors and the little boy's mother for permission to switch off his life support.

The decision came on the seventh day of an emotionally-charged Family Court hearing in which a judge faced the formidable task of deciding whether chronically disabled one-year-old RB should be allowed to live or die in peace after withdrawal of his ventilation.

Lawyers for the health authority caring for the baby in intensive care told Mr Justice McFarlane: "All of the parties in court now agree that it would be in R's best interests for the course suggested by the doctors to be followed."

Declaring that such a course, with palliative care, would be lawful, the judge paid tribute to the young estranged parents who had been "exemplary" in attending to their son at his hospital bedside every day during his short life.

The judge said it was a "sad but in my view inevitable outcome".

It was the "only tenable one for RB".

As the judge summarised the tragic case, both parents wept and the mother at one point left the court in tears but returned to hear his tribute to them and the doctors and nurses caring for their son.

The hospital authority had sought a court order allowing RB to die with dignity rather than continuing to live what doctors described as a "miserable and pitiful" existence.

The father initially opposed the application, arguing his son showed signs of "purposeful" movement when presented with toys and should have the chance to live, even though chronically disabled.

Baby RB was born in October last year with what is thought to be congenital myasthenic syndrome (CMS), a rare neuromuscular condition which severely limits the ability to breathe and move limbs.

Expert medical witnesses described him as having a normal brain locked inside an immobile and "non-communicative" body.

Their principle concern was that he was unable to show, by facial expression or bodily movement, when he was in pain during the stressful treatment he had to undergo, including regular "suctioning" of his airways to remove fluid.

The court heard from counsel that it was a decision the father, AB, had come to "after a very great deal of thought after hearing all the evidence as it has developed in this case".

After being told that all the parties were now in agreement about the course to be taken, the judge said: "It is appropriate for me to say one or two words, not in judgment, but in endorsement of this sad but, in my view, inevitable outcome."

He said: "It is, I suspect, impossible for those of us to whom such an event has not happened to do more than guess at the impact of it upon these two young parents.

"In one moment all of the hopes and dreams that they will have had for their expected baby will have been dashed and replaced with a life characterised by worry, stress, exhaustion, confusion and no doubt great sadness."

He said: "During the past 13 months both KM and AB have discharged their responsibility to their son in a manner which has been described by all who have seen it in superlative terms."

The judge went on: "It is a fact that K and A have spent the most part of each and every day of the last 13 months at RB's bedside, doing what they can to care for him and, when the opportunity arises, to interest and stimulate him, seizing upon any sign of a spark and trying to develop it into something more.

"They have put their own adult lives on hold. The stress has been immense, it has cost them their relationship, but still they work together and do what they can to support their son.

"When faced with the awfulness of the situation in which they found themselves, these two young people have stepped up to the plate and discharged the responsibility that life had thrust upon them by each showing 100% commitment to their child in a manner which can only command profound respect and admiration."

The judge said: "All involved in RB's care, and principally his parents, have recognised for some time that it cannot be in his best interests for him to remain for the rest of his life as an inpatient on a paediatric intensive care unit (PICU).

"Until some 10 years ago, the option for patients who required extensive ventilation were limited but, the court has heard, that pioneering work has been undertaken in developing treatment and support that allows some of these patients to leave hospital and live at home.

"They do so after a tracheostomy operation to their throat, which allows ventilation from a portable ventilation unit.

"In RB's case the choices for his future are stark. There are only two.

"One is for his time on the PICU to end in a planned way, with the administration of a large dose of sedative, the removal of the ventilation tube and his consequent death. The other is to contemplate his discharge from hospital on home ventilation after a tracheostomy.

"At the start of this hearing the treating clinicians and his mother had sadly concluded that the first option was, in the all the circumstances, in RB's best interest. The father contested that conclusion and sought to argue for RB being discharged under the second option."

In RB's case undertaking a tracheostomy and connecting him to a portable ventilator "rather than being a panacea, would simply open up the potential for him to have to endure a further range of procedures and operations".

He added: "The very living of life itself, day by day, hour by hour, is likely to be at best uncomfortable for him and, more probably, regularly painful for him.

"The medical evidence is to the effect that he is likely to feel pain and discomfort in the same manner that any baby does, yet this little boy with his inscrutable features, immobile limbs and soundless voice often gives no outward sign of that which he is feeling."

He added: "I have total confidence in saying that each of these two parents and each of the treating medical team have done all that they could possibly have done to make RB's life as viable, comfortable and enjoyable as it could be.

"I am also fully satisfied that the doctors and scientists have investigated each and every option for RB's future treatment in the manner that I have just described."

A joint statement issued by lawyers representing RB's parents and the hospital trust said: "Although RB's parents separated, they have always been united in wanting the best possible care for their son so that he may have the very best possible quality of life.

"They have been at his bedside daily these last 13 months.

"The court has heard that RB is a dear little boy, adored by his parents, family and the hospital staff.

"Every party in this case has reached this agreement after careful, considered thought for what is in RB's best interests.

"Following the order agreed and approved today, RB's parents and the trust will now make suitable arrangements to bring RB's life to a dignified end in consultation with his parents.

"RB's parents would like to pay tribute to the clinicians, nurses and staff at the trust for their dedicated care for RB.

"Trust staff wish to pay tribute to Miss KM and Mr AB. During the proceedings witnesses on behalf of the trust have repeatedly praised them for their devotion to RB and have understood and respected Mr AB's previous reservations that he wished to see everything done for his son before he could agree to withdrawal of ventilatory support.

"Mr AB has given anxious thought to what is best for RB over many months and has listened carefully to all of the evidence over the last seven days.

"As the evidence has developed he is satisfied that everything has been done for his son and the issues have been fully explored.

"He is now satisfied that the benefits of further medical treatment are sadly no longer in RB's best interests.

"This has been an agonisingly difficult decision.

"RB's parents would now wish to spend what little time remains with their beloved son."

Lawyers stressed that the anonymity order protecting the identities of the parents, hospital trust and health professionals caring for the boy remained in force.

Both parents and the hospital trust asked that their future privacy should be respected.