Jerome Taylor: Why the 'necessity' defence is rarely granted

Tony Nicklinson’s request that any doctor who helps him die should be protected by the common law definition of necessity is a bold one.

English law recognises that there are occasionally circumstances of such overwhelming urgency that a person might be permitted to break the law. However such defences are exceedingly rare and hardly ever granted, especially when it comes to murder.

The case which laid the ground work for the modern legal understanding of necessity – which is different to duress – involved four sailors who were shipwrecked for days off the Cape of Good Hope in 1884. With no fresh water or food, two of the sailors eventually conspired to kill the youngest crewmate, a 17-year-old cabin boy called Richard Parker who was already dying.

The sailors were rescued soon after killing their shipmate and were brought back to Britain where two of them faced a murder trial. Although there was much public sympathy for their plight, both were found guilty of murder. The courts decided that because there was always a chance that a ship might sail over the horizon there was not enough proof of any such necessity which could justify killing the boy.

In more recent times, sufferers of chronic pain who have used cannabis to alleviate their symptoms have also used the necessity argument to justify breaking Britain’s laws on drug possession. But each time the courts have dismissed their plea arguing that other legal medical alternatives are available.

Some human rights lawyers are deeply uncomfortable about any bolstering of the necessity defence because it is more often used in recent times by the police and Government to justify human rights abuses.

When police arrested and held the innocent brother of a September 11 suspect or refused to allow a bus filled with anti-war to attend a demonstration – both of which were acts that were later deemed unlawful in the courts – “necessity” was one of the reasons offered to defend pre-emptive policing.

One of the few times judges have justified a lawful killing on the grounds of necessity is in 2000 when the Court of Appeal allowed doctors to separate conjoined twins that were both going to die if they remained together, even though the operation would kill one of them.

In that particular case a life was extinguished so that another could be spared. Mr Nicklinson’s circumstances are very different. He wants a doctor to be able commit the act of murder to alleviate his intolerable physical, mental and emotional suffering. His necessity is to be freed from living hell that his body has been consigned to.

Ultimately Parliament should be brave enough to begin debating – and potentially legislating for – which circumstances palliative killing might be lawful. Until that happens families like the Nicklinson’s will be forced to drag their pain through the courts.