"In fact, he was sentenced to death by starvation," the archbishop said.
He noted that the man's family was divided over the ruling, leading some family members to seek to challenge the court's decision, without success, at the Court of Appeal and the European Court of Human Rights.
"The European Court of Human Rights in Strasbourg has refused their complaint, which allows the hospital to continue the procedure to deprive this man of his life," Gądecki said.
"The authorities of our country assured that they would cover the costs of treatment and transport. The British court does not agree to transport the patient as the journey may be life-threatening."
He concluded: "I turn to Your Eminence -- as the president of the Catholic Bishops' Conference of England and Wales -- asking for your help in this difficult matter and to undertake steps towards saving the life of our compatriot."
Earlier this month, Bishop O'Toole described the court ruling as "very worrying."
In a statement on Jan. 14, he said: "My prayers are with the patient, his wife and family, and for all those involved in his care. The decision of the court to allow for the withdrawal of hydration and nutrition is very worrying. That it is deemed to be in the best interests of the patient more so."
"Providing food and water to very sick patients -- even if by artificial means -- is a basic level of care. This is care that we must strive to give whenever possible."
Alongside his statement, O'Toole included a link to a press release and briefing paper by the Anscombe Bioethics Centre in Oxford.
Assessing the moral reasoning of the judges in the case, David Albert Jones, the center's director, said that the judgment set "a very worrying precedent."
"The grave danger of this judgment is that committed Catholics and those who hold a similar view about the human significance of food and drink may be starved and dehydrated to death against their will," he wrote.
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