The defence of compulsion may be thought of as a subset of the defence of necessity. The former is, in New Zealand, a statutory, and the latter a common law, defence. The former is an exclusive codification of the circumstances in which compulsion by threats of harm from another person provides a defence: Akulue v R  NZSC 88 (19 September 2013) at .
The Supreme Court distinguished R v Ruzic 2001 SCC 24, in which the facts were similar to those contended for in Akulue, mainly by holding that moral involuntariness is not a principle of fundamental justice engaging the Bill of Rights . Instead, moral involuntariness was properly taken into account in the statutory rules relating to coercion.
Mention was made  of R v Hasan  UKHL 22, noted here on 18 March 2005. Lord Bingham's identification of policy reasons for tightening, rather than relaxing, the conditions to be met before common law duress could be relied on were noted .
The legislative purpose behind the statutory defence is that if there is sufficient time to seek assistance from the authorities, a defence of compulsion is not available, and a belief, whether reasonable or not, that no assistance would be forthcoming is not within the scope of the defence . It was not for the court to extend the bounds of the statutory defence .