The Archbishop of York has appealed to the NHS to reconsider plans to stop paediatric heart services at Leeds General Infirmary.
The NHS review in July 2012 recommended that the surgery should take place at other centres in the country.
The decision is to be re-examined in two independent reviews.
Dr John Sentamu visited NHS staff and patients at the Children's Heart Surgery Unit on Wednesday to show his support.
His visit was made upon the invitation of staff from the unit.
Dr Sentamu said it was "inconceivable" for the service to close.
He has raised concerns with government ministers behind the scenes but yesterday was the first time he spoke publicly about keeping the unit open.
The Archbishop said people should be able to access first class care regardless of where they less.
He called for better coordination of services and "not a culture of winner-takes-all excellence".
"This unit serves the whole region and has saved the lives of so many across Yorkshire and further afield," he said.
"It is inconceivable that we could lose such a fantastic integrated local service.
"We need a strong NHS serving a large number of children. Closing the specialist heart unit at Leeds will have a devastating effect on so many people. It would be terrible news for people across Yorkshire.
"Whilst I understand the difficult economic situation we face as a country, we should not get into a situation where one NHS Trust is played off against another."