France's highest appeals court said Friday that the life support mechanisms keeping a severely brain-damaged man alive can be turned off "from now", a lawyer for his wife said, in the latest legal twist in a landmark right-to-die case.

Vincent Lambert, 42, has been in a vegetative state since a 2008 traffic accident, with the question of whether to continue keeping him alive artificially bitterly dividing his family and the nation.

"This definitely ends the matter," said Patrice Spinosi, legal counsel for Lambert's wife Rachel, who believes the most humane course of action is to let her husband die.

"There is no other recourse possible because there are no more judges to appeal to," he said.

The ruling reverses a decision by another Paris court which last month ordered that Lambert's feeding tubes be reinserted, just hours after doctors began switching off life support.

The Cour de Cassation did not consider the arguments for or against keeping Lambert alive, but only the question of whether the lower court was competent to rule on the case, which has taken the warring Lambert family to the top tribunals in France and Europe.

His parents, who are devout Catholics, have fought a six-year legal battle to maintain treatment against the wishes of his wife and doctors.

Lambert's wife, six of his siblings and a nephew had been hoping that Friday's decision would end the legal battle once and for all.