Necessity as public policy
unjust to punish a defendant for doing something that a reasonable person
would have done in the same circumstances;
should encourage a defendant to choose the lesser and avoid the greater
evil on grounds of public policy.
Re Sigsworth 1935
S murdered his mother and tried
to claim his inheritance. There is a rule that no one should profit from
his or her wrong, this overruled a clear statutory right of a son to
inherit on intestacy. Hence statutes may be modified on grounds of public
policy, as one was in this case (the principle was an existing
common law principle that would have applied had she had died having made
a will). Although this is a clear breach of the rule that clear and
unambiguous words cannot be ignored, it surely accorded with Parliament's
R v Howe  HL
[Duress not available in murder
D acting under duress, took part with others in two separate murders, and
on a third occasion the intended victim escaped.
Using the 1966 Practice Statement to depart from the decision in Lynch.
not available as a defence to murder either to a principal or accessory.
Morals, law and policy should deny a man the right to take an
innocent life even at the price of his own.
overriding objects of the criminal law must be to protect innocent lives
and to set a standard of conduct which ordinary men and women are
expected to observe if they are to avoid criminal responsibility…"
BC v Williams  CA
[Duress and necessity policy
A homeless family squatted in an empty Council house, and resisted the
Council's efforts to evict them.
Lord Denning MR;
were allowed as an excuse for stealing, or homelessness as a defence to
trespass, it would open a door through which all kinds of lawlessness and
disorder would pass; each would say his need was greater than the next
Whiston v Whiston 1995
Public policy reasons
prevented someone who had had a bigamous marriage (and was hence void),
claiming money that they were clearly statutorily entitled to.