Lambert’s devout Catholic parents said they had “new elements” to challenge the decision by the court on 5 June to withdraw life support.
The fate of Lambert, 38, who was left quadriplegic and in a vegetative state following a road accident in 2008, has torn apart his family in a judicial tug-of-war over his right to die.
The legal struggles started in 2014 when Lambert’s doctors, his wife and six of his eight siblings decided to stop the intravenous food and water keeping him alive.
But Lambert’s parents, half-brother and sister won a court application to stop the plan, calling it “akin to torture”.
Then the French supreme administrative court ordered doctors to draw up a report on Lambert’s condition and ruled in June 2014 that withdrawing care from a person with no hope of recovery was lawful.
His parents and two siblings then appealed to the European Court of Human Rights about the French court decision allowing Lambert to die.
But the European court on 5 June voted that the French decision did not violate European rights and that Lambert should be allowed to die.
His wife insists that Lambert, a former psychiatric nurse, would never have wanted to be kept alive artificially.
Lambert’s case ignited a fierce debate in France over euthanasia where it remains illegal despite recent efforts to ease legislation dealing with the terminally ill.