Doctors on Tuesday resumed the life support for a Frenchman who has been in a vegetative state for over a decade, following a court order to restore it hours after the switching off process began, lawyers said.

"We have the pleasure to inform you that... the hydration and feeding of Vincent Lambert has been resumed," said Jean Paillot, a lawyer for the parents who vehemently oppose ending his life, after a ruling late Monday by the Paris appeals court. 

The legal saga for Mr Lambert (pictured) has lasted over half a decade. Photo: AFP

"It is not a suspension but a new start," added the parents' other lawyer Jerome Triomphe who said the aim now was to have Lambert transferred to a different hospital.

The Paris court ordered authorities "to take all measures" to keep alive Lambert, a 42-year-old quadraplegic with severe brain damage, pending a review by the UN Committee on the Rights of Persons with Disabilities.

Earlier Monday, the European Court of Human Rights in Strasbourg had rejected a request by the parents to halt the decision over the cessation of life-support pending the review by the UN committee.

Doctors in France Monday morning halted the nutrition and hydration Lambert receives, which is in line with the wishes of his wife and other relatives but sparked the anger of the parents.

The legal saga over the fate of Lambert, who has been kept alive after a traffic accident in 2008, has lasted over half a decade, split his family and divided France.

Lambert's parents, devout Catholics, have repeatedly launched court action to keep him alive, putting them at odds with Lambert's wife and six siblings who believe the most humane course is to let him die.

Before the latest court ruling, Pope Francis had weighed in Monday in favour of keeping Lambert alive.

"Let us always safeguard life, God's gift, from its beginning until its natural end. Let us not give in to a throwaway culture," the pontiff said.

The issue has also taken on a political importance in France in the midst of the campaign for European elections.

French President Emmanuel Macron Monday rejected calls by Lambert's parents and others to intervene, saying "the decision to stop treatment was taken after a constant dialogue between his doctors and his wife, who is his legal representative."

The UN committee on disabled rights had this month asked France to suspend the decision while it conducts its own investigation, which could take years.

The French government has said it will note the committee's deliberations but made clear there was no legal obligation for it to abide by them.