A British man who is terminally ill with motor neuron disease asked the High Court in London on Monday to let him end his life.
Noel Conway is challenging Britain's ban on assisted suicide, arguing it is incompatible with protections of human rights.
Conway, 67, was diagnosed with the degenerative condition in 2014 and is expected to die within a year. He says that when he has less than six months to live and retains the mental capacity to make the decision, he wishes to be able to enlist assistance to bring about a "peaceful and dignified" death at a time of his choosing.
"I know I am going to die anyway, but how and when should be up to me," he said.
A previous challenge to Britain's ban on assisted dying by another man was rejected in 2014 by the Supreme Court. The court said Parliament should debate the issues before any decision was made by the courts.
Lawmakers have so far declined to change the 1961 Suicide Act, which makes it illegal to help another person kill themselves.
Disability rights group Not Dead Yet U.K. said it sympathized with Conway, but opposed an attempt to change the law on assisted dying.
"A change in the law is a terrifying prospect to the vast majority of disabled and terminally ill people who work hard towards achieving equality for all," said its co-founder, Phil Friend.
The hearing before three judges is scheduled to last five days, with a decision not expected for several weeks.
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