By Law Teacher

10.2.1 Duress and Necessity – Introduction

Welcome to the tenth topic in this module guide – Defences! When a defendant is charged with a crime, there are several ways in which he possibly could go about attempting to exonerate himself of legal responsibility, reduce his liability or lessen his sentence. This can be done through arguing the facts of a case, arguing a case on a point of law, arguing mitigating circumstances or establishing a defence in his favour. In law, there exists many different types of defences, and one defence may fall under a multitude of categories.

This topic in this module focuses on two different defences: duress and necessity. The defence of duress applies where the perpetrator’s choice was constrained as a result of threats to commit an otherwise criminal act, whereas necessity applies where the perpetrator has an inhibited choice due to exceptional circumstances. Duress and necessity are both excusatory defences, and as such, apply when the accused admits they committed a criminal act but that their actions can be justified, and therefore they should not be criminally culpable.

Goals for this section:

  • To understand the elements that must be satisfied in order to successfully raise a defence of duress or necessity.
  • To comprehend in what scenarios the defences of duress and necessity can be utilised.
  • To appreciate the effect of a successful plea of duress and necessity.

Objectives for this section:

  • To appreciate the delineation between duress by threats, as established in the case of Whelan, and duress by circumstances.
  • To be able to recognise the importance of the development of case law for both of the defences.
  • To be able to analyse and evaluate the nuances of both of the defences, as required in an examination.

10.2.2 Duress and Necessity Lecture

1.0 Duress

Duress applies as a defence where a person commits a crime as a response to a threat of death or serious injury either to themselves or another.

The defence of duress is a general defence but there are certain limitations on its use. In cases where the defence of duress is pleaded successfully it has the effect of absolving the defendant of liability. This is because whilst he clearly possesses the requisite mens rea for the offence, in carrying out the actus reusthey are acting under compulsion and not through choice, thus it is not a voluntary act.

1.1 Types of Duress

In criminal law the defence of duress takes two different forms.

1.1.1 Duress by Threat

The defence of duress by threat was set out in A-G v Whelan [1993] IEHC 1 as arising in circumstances where the defendant was ordered to commit an offence whilst subject to threats of immediate death or serious personal violence so great as to overbear the ordinary powers of human resistance.

1.1.2 Duress by Circumstance

Duress of circumstances arises where it is not a person that provides a threat to the defendant but the nature of the situation. It might be that another person creates the threatening situation but unlike duress by threat there is no requirement that a person specifies to the defendant that a crime must be committed, so long as there is a sufficient link between the situation and the crime.

1.2 Elements of the Defence

The defence applies similarly in relation to both duress by threat and duress of circumstances and both are governed by the same criteria. Accordingly, most of the cases are authority for both forms of the defence.

The defence was set out in R v Graham [1982] 1 All ER 801. It set out two elements to the defence:

  1. Was the defendant or might the defendant have been induced to act as he did because he feared that if he did not, death or serious injury would result to him, an immediate relative or someone he is responsible for?
  1. Would a sober person of reasonable firmness, sharing the defendant’s characteristics have acted in the situation in the way as he did?

If these elements can be shown then the following must also be shown for the defence to succeed:

  • There must be immediacy, and;
  • The defendant must not have missed an opportunity to escape the threat without committing a crime.

Finally, even where this has been established, following the ruling in R v Hasan [2005] 2 AC 467 the defence will be excluded where a person who voluntarily becomes involved in or remains involved with people who are engaging in criminal activity and ought to reasonably have foreseen the possibility of becoming the subject of compulsion by them or associates known to them.

In all cases, the question is for the jury to decide whether the threat that the defendant was exposed to was serious enough so as to outweigh the seriousness of the offence committed.

1.3 The Defence Explained

  • Specified crime
  • Immediacy
  • Facing a threat of death or serious injury
  • To the defendant or a person for whom he has responsibility
  • The threat must overbear the ordinary powers of human resistance.

Specified crime

In relation to duress by threat, the threat issued must be accompanied by instruction to commit a specified crime.

Case in Focus

R v Cole 1994 Crim LR 582


The requirement for immediacy is broad and does not require immediacy in the strict sense of the word.

Case in Focus

R v Hudson and Taylor [1971] 2 QB 202 and R v Abdul Hussain [1999] Crim LR 570

Where there is an opportunity to take evasive action to negate the threat then Hasan suggests that this will negate the immediacy.

Facing a threat of death or serious injury

This element is fairly self-explanatory and sets out that the threat that the defendant faces must be one of death or serious injury.

Case in Focus

R v Valderamma-Vega [1985] Crim LR 220

To the defendant or a person for whom he has responsibility

As above, this element is clear in that the threat that arises from the individual or the circumstance must be a threat against either the defendant himself or a person which the defendant has responsibility for. This would include for example family members.

Case in Focus

R v Shayler [2001] 1 WLR 2206

In contrast to Shayler, in some instances the situation existing can place the defendant in a position where he is responsible for the person in question.

Case in Focus

R v Conway [1989] QB 290

The threat must overbear the ordinary powers of human resistance.

The objective arm of the Graham test acts so as to establish whether the threat faced would cause a reasonable person to act in the same way. The way of establishing that is to ask whether the given threat was so great that it would overbear the powers of ordinary human resistance. This focuses on three points:

  1. a reasonable belief
  1. a good cause of fear
  2. a sober person of reasonable firmness, sharing the characteristics of the defendant might act the same.

In applying this test, some but not all of the characteristics of the defendant may be taken into account. A recognised medical condition causing the defendant to have a reduced firmness can be taken into account but a general nervous disposition cannot.

1.4 When can the defence be used

As explained in the introductory notes, the defence of duress is a general defence and is available to raise in response to most charges, however there are some exceptions. The defence is not available in the following situations:

  • Hasan confirms that the defence is not available in response to a murder charge. R v Gotts [1992] 2 AC 412 states that the defence is also not available to attempted murder.
  • The defence is not available in response to a charge of treason.
  • Following R v Sharp 1987 1 QB 853, the defence is also excluded in cases where the defendant of his own will and with knowledge of the nature of the group, joins a violent criminal gang. Similarly to the gang exemption, the defence is unavailable where the defendant voluntarily joins a terrorist group.
  • Following on from the above, where the defendant becomes indebted to drug dealers he will not be able to use the defence.
  • Due to the immediacy requirement, the defence will become obsolete in cases where the defendant had opportunity to or could reasonably have taken evasive action

2.0 Necessity

2.1 Concept of Necessity

This defence arises where the defendant successfully argues that due to a greater evil, it was necessary to commit the offence that he carried out. He had a choice between committing a criminal offence or allowing himself or another to suffer. Self-defence is another example of necessity embodied in a more narrowly defined defence.

Case in Focus

R v Dudley and Stephens(1884) 14 QBD 273

Lord Denning echoed the sentiment expressed in Dudley and Stephens in the case of Southwark London Borough Council v Williams [1971] Ch 734 stating in his judgement that the defence of necessity would open a door which no man could shut.

2.2 Requirements of the Defence

The idea of a general necessity defence was discussed Gillick v West Norfolk and Wisbeck Area Health Authority [1986] AC 112. The defence was then recognised by Lord Goff in Re F (Mental patient sterilisation) [1990] 2 AC 1.

Case in Focus

Re F (Mental patient sterilisation) [1990] 2 AC 1

Following the recognition of the defence, the case of Re A [2001] Fam 149 took this further, confirming the decision in Re F and holding that it could even be used as a defence to murder.

Case in Focus

Re A [2001] Fam 149

The reasoning behind the decision in Re A was that the Court believed the operation was necessary, and thus the doctors would be afforded the defence in relation to the operation. The requirements that must be filled in order for this defence to apply were set out by Lord Justice Brooke. These are that

  1. the act is needed to avoid inevitable and irreparable evil;
  1. no more should be done than is reasonably necessary for the purpose to be achieved, and;
  2. The evil inflicted is not disproportionate to the evil avoided.

Following R v Quayle [2005] EWCA Crim 1415, a fourth criteria was added:

(iv) The necessity must have arisen in extraneous circumstances

And finally, following the ruling in Shayler, a fifth criteria became necessary:

(v) The evil must be directed towards the defendant himself or someone who he had responsibility for.

2.3 Necessity in practice

The case of Re A recognised that the defence could be applied but due to the restrictive criteria set out and subsequently added to, the reality of a general defence of necessity is not an easy defence to argue in practice. In fact, most of its success has been limited to medical cases to protect professionals and allow for patient’s best interests to be looked after. It has not yet gone so far as to protect patients acting in their own best interests in relation to self-medication cases.

Case in Focus

R v Quayle [2005] 1 WLR 3642

However, again protecting medical professionals, the Home Office agreed with the Pharmaceutical Society of Great Britain that in relation to drug trials it could be necessary to use cannabis.

Outside of the medical arena the defence of duress of circumstances may afford a better route to defendants. This defence is still very restrictive but the court’s are more open to hearing this defence as it is not accompanied by the public policy fear of opening the flood gates to justifying immoral behaviour.

2.4 Arguments for a General Defence

  1. Taking into account the defendant’s motive

The law holds that a person should only be responsible for acts of their own free will.  The defence of automatism supports this whereby the defendant who carries out an act due to an internal or external factor that deprives them of their free will is afforded a defence. This defence limits the recognition to a physical inability to exercise free will but does not encompass a circumstantial inability whereby although the defendant may physically be able to control his actions, realistically he has no choice but to act as he does, thus depriving him of his free will.

(ii) Impossible standards of morality

Not recognising a defence of necessity sets a standard whereby the law expects individuals to exercise good morals and obedience to the law above the basic human instinct of survival. Consider the case of Dudley and Stephens. Realistically, can it be reconciled with Re A, other than the fact that Dudley and Stephens were not medical professionals? A decision was taken to kill the person least likely to survive, the cabin body in Dudley and Stephens and baby Mary in Re A. In both cases the decision was taken in order to effectuate the survival of the others, and in both cases if the decision had not been taken all parties involved would likely have met their death. In any case, this standard of morality handed down by the law is exceptionally high so as to criminalise human beings fighting for their survival in dire circumstances whilst at the same time imposing no liability for a duty to act on an adult walking by a child drowning in a lake. It can be argued that the law is inconsistent in this respect and should take a more level approach to the standard of morality expected from people.

(iii) Other jurisdictions recognise the defence

A general defence of necessity is recognised in many other countries and seemingly they still maintain a good level of lawfulness.

10.2.3 Duress and Necessity Lecture – Hands on Examples

The following problem question is designed to test your knowledge of the defence of duress and give you an opportunity to try and apply the elements of the defence in a practical context in response to an offence committed. Defence problem questions are not like other problem questions on offences where you establish the actus reus and mens rea and then apply them to see if they are fulfilled, so it may take a few attempts at them to adjust your style before you feel really confident at tackling them!

Take a look at the following scenario and identify any material facts as you read. Once you have done this, try and apply the defence using the case law we have looked at in these notes.

If you’re not feeling too confident about the question or the application of the defence there is absolutely no need to be concerned! Defences can and will take time to get your head around. By looking at exam style questions you are taking the right steps towards getting properly acquainted with them and when you have done enough it will become second nature! For now, a step by step outline answer has been set out and this contains all the points you need to follow and discuss when you address the scenario. Try and implement the structure and use this as guidance in writing or checking your own answer. Everything you need to know to answer this question has been discussed already so refer back to the notes to help you as you go. Good luck!

Aaron lives in an estate just outside Birmingham city centre. On the estate, there is a well-known group of lads that supply drugs around the estate. They make a lot of money and always sport designer brands and have the latest technology but they have a fearsome reputation and many of the members of the gang have been in prison at some point for violent crimes against other dealers and people who have been indebted to them. Aaron approaches the gang leader, Dean and tells him he wants in. Aaron is a little scared as he knows of the gangs reputation but Dean tells him  as long as he stays on the right side of him he has nothing to worry about. For a few weeks things go well and Aaron makes a lot of money. He starts going to the casino and one night he loses massively at poker and ends up owing a lot of money to another player. Aaron pays up by giving him all the money from his drug sales that week. He is supposed to give the money to Dean’s right hand man Jay who takes the proceedings and then pays Aaron a cut out of that. When he goes to Jay with no money Jay is livid and tells Aaron that he must pay the money back by the next morning, even if he has to steal it, or he will be killed. Aaron knows that his brother’s girlfriend Susie is very well off and has seen her wear a diamond necklace. He decides to break into Susie’s house that night and steal the necklace. He sells it the next morning and is able to repay Jay in time to avoid the threat.

Aaron is subsequently charged with the burglary. Discuss Aaron’s ability to raise the defence of duress


  • What type of duress?
  • Duress by threat as per A-G v Whelan as Jay has posed a verbal threat to Aaron.
  • Applying R v Graham, have all the elements of the defence been satisfied?
  • Specified crime: Jay has suggested to Aaron that he might need to steal to get the money but he has not specified exactly what he should steal or where from. Applying Cole, although the general offence of theft has been suggested this is not an absolute must as Jay is seemingly not bothered how he gets the money, as long as he gets it. This could, therefore, be argued either way on the facts as long as you support your decision with reasoning.
  • Immediacy: Applying R v Hudson and Taylorand Abdul Hussain this requirement is broad, and therefore is not definitely negated by the fact that the harm will come in the morning, as long as the threat is present. However Hasan suggests that an opportunity to take evasive action or prevent the threat will negate any immediacy. In this case, it could be argued that Aaron had ample time overnight to go to the police station but given the nature of the fact he was operating within a gang of people it is possible that this would not have negated the threat posed to him as one of the other gang members such as Dean would likely carry out the threat of death as revenge for grassing Jay up.
  • Facing a threat of death or serious injury: In this case it is clear that Aaron is facing a threat of death.
  • To the defendant or a person for whom he has responsibility: The threat is towards Aaron so this element is clearly satisfied.
  • The threat must overbear the ordinary powers of human resistance: This is an objective test looking at a person of reasonable firmness in the circumstances of the defendant. On the facts Aaron does not have any relevant characteristics that would give him a reduced firmness and it is likely that a such person of reasonable firmness facing a real threat of death might have behaved in the same way.
  • Can the defence be used?
  • The defence can be applied in relation to burglary as it is not one of the excluded offences. However applying Hasan, the defence will not be possible where the defendant has knowingly involved himself in a criminal organisation and should have reasonably foreseen that he may become the subject of their compulsion. Given the gang’s reputation it will be difficult to argue that Aaron would not have reasonably foreseen that, particularly as it is stated that he was nervous approaching Jay because of this.
  • Given this it is highly unlikely that Aaron will not be able to avail himself of the defence of duress.