Critically evaluate the operation of the defence of necessity in England and Wales.
Introduction
In Conway and Martin, duress of circumstances is treated by the courts as a defence
of necessity. The general meaning of the defence of necessity in criminal law is where the
defendant is arguing that it was necessary for them to commit a crime, it often operates
where the defendant has two alternatives either commit a crime or suffer or cause
another extreme hardship.1 Necessity relates to the situation where a person commits an
offence to avoid the greater evil to himself or another which would ensue from objective
dangers arising from the circumstances in which he or that other placed. To apply the
defence of necessity, Sir James Stephen stated that there are three requirements to be
satisfied2; i) the act is needed to avoid inevitable and irreparable evil. ii) no more should be
done than is reasonably necessary for the purpose to be achieved. iii) the evil inflicted must
not be disproportionate to the evil avoided.
The necessity defence was constructed by judges who sensed that a defence was
appropriate in certain cases despite recognising that the cases failed to fit the model of any
other affirmative defence.3 But yet, in this form, a necessity is not a defence to murder, one
of the most famous case in English Law which is regarded is Dudley and Stephens4.
However, it should be noted that the courts have not accepted a general defence of
necessity. The straightforward claim, “I broke the law but there would have been worse
1
Reference to: e-lawresources.co.uk, “The Defence of Necessity”,
URL: http://www.e-lawresources.co.uk/Defence-of-Necessity.php accessed on 25 May 2014.
2
Reference to: J F Stephen, A Digest of the Criminal Law, (4th edn Macmillan and Co, London 1887)
3
Reference to: G Yaffe, ‘A Procedural Rationale for the Necessity Defence’, ProQuest 2009.
4
Reference to: Dudley and Stephenson (1884) 14 QBD 273.
1
, consequences had I obeyed the law, will not in itself lead to an acquittal. 5 Hobart J in Moore
v Hussey stated that:
“All laws admit certain cases just excuse, when they are offended in the letter and
where the offender is under necessity, either of compulsion or inconvenience.’
His principle conceded that necessity might justify conduct which would otherwise be
unlawful.
Distinction between necessity and duress of circumstances
In Shayler, the Court of Appeal discussed the relationship between duress of
circumstances and necessity. Lord Bingham and Lord Hutton made it clear that they did not
necessarily agree with all that was said about these defences. 6 Perhaps some judicial
reluctance to recognising a defence of necessity was due to the general belief that it
operated as a jurisdiction. In Canada in Perka et al v The Queen, the Supreme Court of
Canada held that necessity should be recognised in Canada as an excuse thereby implying
‘no vindication of the deads of the actor’. 7 Thus the defence was seen as a concession to
human frailty and was based on ‘society’s expectation of appropriate and normal resistance
to pressure’.8
There are important differences between the two defences. The two cannot be the
same if, as Re A establishes, necessity may be a defence to murder, at least in medical
5
Reference to: Quayle [2005] EWCA Crim 1415.
6
Reference to: D Ormerod, Smith and Hogan Criminal Law Cases and Materials, (10th edn Oxford 2013) pg.
490.
7
Reference to: Perka et al v The Queen (1984) 13 DLR (4 th) 1.
8
Reference to: M J Allen, Textbook on Criminal Law, (12th edn Oxford 2013) pg. 200.
2
Introduction
In Conway and Martin, duress of circumstances is treated by the courts as a defence
of necessity. The general meaning of the defence of necessity in criminal law is where the
defendant is arguing that it was necessary for them to commit a crime, it often operates
where the defendant has two alternatives either commit a crime or suffer or cause
another extreme hardship.1 Necessity relates to the situation where a person commits an
offence to avoid the greater evil to himself or another which would ensue from objective
dangers arising from the circumstances in which he or that other placed. To apply the
defence of necessity, Sir James Stephen stated that there are three requirements to be
satisfied2; i) the act is needed to avoid inevitable and irreparable evil. ii) no more should be
done than is reasonably necessary for the purpose to be achieved. iii) the evil inflicted must
not be disproportionate to the evil avoided.
The necessity defence was constructed by judges who sensed that a defence was
appropriate in certain cases despite recognising that the cases failed to fit the model of any
other affirmative defence.3 But yet, in this form, a necessity is not a defence to murder, one
of the most famous case in English Law which is regarded is Dudley and Stephens4.
However, it should be noted that the courts have not accepted a general defence of
necessity. The straightforward claim, “I broke the law but there would have been worse
1
Reference to: e-lawresources.co.uk, “The Defence of Necessity”,
URL: http://www.e-lawresources.co.uk/Defence-of-Necessity.php accessed on 25 May 2014.
2
Reference to: J F Stephen, A Digest of the Criminal Law, (4th edn Macmillan and Co, London 1887)
3
Reference to: G Yaffe, ‘A Procedural Rationale for the Necessity Defence’, ProQuest 2009.
4
Reference to: Dudley and Stephenson (1884) 14 QBD 273.
1
, consequences had I obeyed the law, will not in itself lead to an acquittal. 5 Hobart J in Moore
v Hussey stated that:
“All laws admit certain cases just excuse, when they are offended in the letter and
where the offender is under necessity, either of compulsion or inconvenience.’
His principle conceded that necessity might justify conduct which would otherwise be
unlawful.
Distinction between necessity and duress of circumstances
In Shayler, the Court of Appeal discussed the relationship between duress of
circumstances and necessity. Lord Bingham and Lord Hutton made it clear that they did not
necessarily agree with all that was said about these defences. 6 Perhaps some judicial
reluctance to recognising a defence of necessity was due to the general belief that it
operated as a jurisdiction. In Canada in Perka et al v The Queen, the Supreme Court of
Canada held that necessity should be recognised in Canada as an excuse thereby implying
‘no vindication of the deads of the actor’. 7 Thus the defence was seen as a concession to
human frailty and was based on ‘society’s expectation of appropriate and normal resistance
to pressure’.8
There are important differences between the two defences. The two cannot be the
same if, as Re A establishes, necessity may be a defence to murder, at least in medical
5
Reference to: Quayle [2005] EWCA Crim 1415.
6
Reference to: D Ormerod, Smith and Hogan Criminal Law Cases and Materials, (10th edn Oxford 2013) pg.
490.
7
Reference to: Perka et al v The Queen (1984) 13 DLR (4 th) 1.
8
Reference to: M J Allen, Textbook on Criminal Law, (12th edn Oxford 2013) pg. 200.
2
