Judges have turned down an appeal bid against a decision to stop life support for brain-damaged baby Isaiah Haastrup.
Last month, the High Court gave doctors permission to stop treatment for the one-year-old, against his parents' wishes.
Specialists at King's College Hospital in London said giving further intensive care was "futile, burdensome and not in his best interests", and suggested only palliative care.
The Court of Appeal has now upheld that decision and denied his parents permission to appeal.
Isaiah's father, Lanre Haastrup, has been banned from visiting his son at London's King's College Hospital and on Thursday also lost an appeal to have that overturned.
Speaking after the decision, he said the hospital "should be ashamed of themselves – the way they've treated us".
"How can you ban me from seeing my son despite having a judgment in there to kill him – for him to die.
"It's really sad – it's a sad day – where are we going in this country that a father has been banned with no criminal act?"
Mr Haastrup told reporters he believed the judges had "got it wrong" by not hearing evidence over treatment for his son, who he says is still responsive.
"We haven't heard what experts have to say about this treatment," ha added,
"What their lordships should have done is at least hear from the experts who will come an examine Isaiah and then make a decision from that.
"All they've done is read some peer-reviewed articles and then said 'no, it's not going to work'. It's really sad."
Isaiah's father said the hospital had not told them when Isaiah's life support would be switched off, but that the family was planning an appeal to the European Court of Human Rights.
"They should wait and see what we do next – they shouldn't rush to kill him – to end his life," said Mr Haastrup.
Isaiah suffered serious brain damage due to being deprived of oxygen at birth.
Lawyers for King's College Hospital have said he is in a low level of consciousness and cannot move or breathe independently.
Doctors also say Isaiah does not respond to stimulation – a claim he parents reject.
His mother, Takesha Thomas, previously told judges: "When I speak to him he will respond, slowly, by opening one eye.
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"I see a child who is injured. He needs love. He needs care. I have it. I can give it. To say it is so poor, it is not worth living, that is not right. It is not their decision to make."