LONDON -- The British parents of a terminally ill baby, facing another court hearing on his condition and care, said Sunday they are hopeful he will receive the experimental treatment previous rulings have prevented.

"If he's still fighting, we're still fighting," said Connie Yates, mother of 11-month-old Charlie Gard. Yates and Charlie's father, Chris Gard, spoke outside London's Great Ormond Street Hospital, where the baby is in intensive care and on life support.

The baby's parents have received support from Pope Francis and U.S. President Donald Trump, but Charlie's future remains in the hands of British courts charged with determining what is best for him.

"He's our son; he's our flesh and blood. We feel that it should be our right as parents to decide to give him a chance at life," said Yates, carrying a petition signed by about 350,000 people supporting the couple's quest.

"There is nothing to lose; he deserves a chance."

The complex case appeared to have reached its end last month, when the European Court of Human Rights refused to overturn British court rulings barring Charlie from traveling to the United States for treatment.

The hospital intended to turn off life support systems in favor of "palliative" care designed to ease any pain the baby might be experiencing.

But the case took a turn when researchers at the Vatican's children's hospital, which has offered to treat Charlie, said new information suggested the experimental treatment sought by the parents might be effective.

That prompted the hospital to seek another High Court ruling.

A hearing where the new medical information is likely to be examined is expected to take place today.

Clinicians from the Vatican's Bambino Gesu pediatric hospital's neurosciences department said tests in mice and patients with a similar but not identical genetic condition as Charlie had shown significant improvement is possible.

At present, the boy isn't able to breathe unaided. He has a rare inherited mitochondrial disease that has affected many of his vital organs and left him with brain damage.

An online campaign to send Charlie to the U.S. for treatment has raised more than $1.7 million.