The defence is limited as the courts are generally not prepared to accept it.
The D are placed in a position where they believe they have to commit an offence in order to prevent a worse evil from happening
Necessity - Dudley and Stephens
The defence was not allowed for the crime of murder, although the usual sentence of death was reduced to 6 months imprisonment.
Necessity - Southwark v Williams
Lord Denning stated that if allowed “necessity would open a door which no man could shut… the courts must take a firm stand”
Necessity - has been allowed in medical cases
Re F
-> courts held that it would be lawful for F to be sterilised without her consent as she had the mental capacity of a child of 4, Lord Goff said necessity was the justification for this
Necessity - Re A, requirements for the application
LJ Brooke:
where an act was done to avoid consequences which couldn’t be avoided
the consequences would have inflicted inevitable and irreparable evil
no more was done than was reasonably necessary
the evil inflicted was not disproportionate to the evil avoided
Necessity - Shayler
Adds a further criteria:
The evil must be directed towards the D or someone for whom they have responsibility
