Dr. Paul Saba has been battling the notion of medically-assisted death since before it became law in Quebec and Canada.

He is not stopping now.

He said Sunday that the possibility of a medical error or misdiagnosis is one of the many reasons why dying with the help of a physician should be illegal.

"It's 10 to 20 percent depending on what studies you look at. We're talking about serious diagnostic errors enough that in the United States would lead to medical malpractice," said Dr. Saba.

Alexandre Montreuil said he was misdiagnosed, and would have ended his life if that was a legal option.

"At first when I had the first diagnosis of cancer and I had a couple friends that went through it I didn't want to go there at all," said Montreuil.

He was misdiagnosed in 2004.

"If it wasn't for that doctor I would have said goodbye to this world," said Montreuil.

But Jean-Pierre Menard, a patients' rights lawyers, said Saba's arguments are not realistic.

"You must have an advanced decline of your capacity. That could not occur if you have been misdiagnosed," said Menard.

To prevent abuse, Bill 52 only allows doctors to administer a lethal injection if a person is mentally fit, with an incurable illness, in unbearable physical and/or psychological pain and in an advanced state of irreversible decline.

Patients can also change their mind at any time.

"At that time the patient will have the choice to decide if they want palliative care or not. It is fully his right to decide at any time to stop, refuse, or drop at any time palliative care and get access to medical aid in dying," said Menard.

Since December, 166 Quebecers have ended their lives with medical assistance.

In the meantime Saba said he will continue to oppose both the federal and provincial laws.

That's something Menard does not think Saba will win since the decision to end a life belongs to a patient, and not a doctor.