Overview
Trespass to the person comprises three distinct torts: battery, assault, and false imprisonment. Even where a claimant establishes the elements of one of these torts, the defendant may escape liability by relying on a recognised defence. The principal defences available in English law are consent, lawful arrest, self-defence, defence of property, and necessity. Importantly, contributory negligence is not available as a defence to trespass to the person, a position now firmly established by the courts.
Consent
Express and Implied Consent
Where a claimant has expressly or impliedly consented to the defendant's act, the defendant will not be liable in trespass to the person. Consent may arise in a wide variety of contexts. Surgical operations and medical treatment provide the most obvious examples: a patient who agrees to an operation consents to the physical contact that the procedure necessarily involves. Similarly, participation in contact sports carries an implied consent to the physical contact that is inherent in that activity.
Medical Treatment and Consent
A question arises where a doctor obtains a patient's consent but fails to disclose the risks associated with the proposed treatment. In such circumstances, no claim in trespass to the person will lie; the appropriate cause of action is instead in negligence. This distinction was established in Chatterton v Gerson [1981], where it was held that once a patient is informed in broad terms of the nature of the procedure and consents to it, that consent is real and valid for the purposes of trespass. Any failure to advise the patient of specific risks sounds in negligence rather than in battery. This approach was subsequently confirmed in Chester v Afshar [2004], which further developed the law on a doctor's duty to disclose risks of treatment within the negligence framework.
Sports and Consent
A participant in a competitive sport consents not only to all conduct that falls within the rules of the game, but also to conduct which may fall outside those rules to the extent that such conduct remains within the spirit of the particular sport. In Condon v Basi [1985], the court held that a footballer consented to a tackle that was foul but within the range of conduct to be expected in the sport. However, consent will not extend to conduct that is entirely outside the spirit of the game or is deliberately intended to cause injury.
Lawful Arrest
A police officer who lawfully arrests a person pursuant to a valid warrant and uses only reasonable force in effecting that arrest does not commit the tort of battery. The key requirements are that the arrest must be lawful — grounded either in a valid warrant or in a statutory power of arrest — and that only such force as is reasonably necessary in the circumstances may be used. Any force that exceeds what is reasonable will not be protected by this defence, and the officer may incur liability for battery in respect of any excess.
Self-Defence
Requirements
For the defence of self-defence to succeed, three conditions must be satisfied. First, the force must have been used genuinely in self-defence and not as an act of retaliation. Second, the force used must be reasonable. Third, the force must be proportionate to the force used or threatened by the claimant. Where the defendant retaliates after the threat has passed, or uses force wholly disproportionate to the threat faced, the defence will fail.
Scope and Limits of the Defence
The leading authority is Cockcroft v Smith [1705], in which the court confirmed the requirements set out above. The self-defence defence extends beyond the protection of the defendant personally: it also applies to the protection of other members of the defendant's family and, in an employment context, to the protection of the defendant's employer or employee. However, there is no clear authority supporting the extension of the defence to the protection of third parties generally beyond these established categories. Any defendant who seeks to rely on self-defence in circumstances outside these recognised boundaries should be aware that the scope of the protection afforded remains uncertain.
Defence of Property
Requirements
A defendant may use reasonable force to protect property, but the defence is subject to important limitations. The principles were established in Green v Goddard [1702]. Three requirements must be satisfied. First, no more force may be used than is strictly necessary for the purpose. Second, where the defendant's aim is to eject a trespasser from the property, the defendant must first request that the trespasser leave before resorting to any physical force. Third, where force is necessary, it must be reasonable in all the circumstances.
Limits of the Defence
As with self-defence, Green v Goddard [1702] makes clear that there is no clear authority permitting a defendant to use force in defence of another person's property. The defence is therefore confined to the protection of the defendant's own property, subject always to the requirements of necessity and proportionality.
Necessity
Scope of the Defence
The defence of necessity may apply in circumstances where an adult is given medical treatment without their consent. The classic scenario is an emergency situation in which the patient is unconscious and therefore unable to consent. More broadly, the defence may operate where there exists a state of affairs — whether temporary or permanent — that renders the patient incapable of giving consent. The defence is not confined to medical professionals: it may also extend to bystanders who render assistance at the scene of an accident, and to care workers attending to those in their charge.
The Best Interests Requirement
The leading case is F v West Berkshire Health Authority [1989], in which the House of Lords held that a doctor who treats an incapacitated patient without consent will not be liable in trespass to the person, provided that the treatment is in the best interests of the patient. The best interests requirement is central to the defence: the action taken must genuinely serve the interests of the claimant and must not go beyond what is reasonably required to address the immediate situation. Acts motivated by the interests of third parties or by considerations of public convenience will not be protected.
Contributory Negligence and Provocation
The Principle: No Defence Available
Contributory negligence is not available as a defence to a claim in trespass to the person. Equally, provocation — whether by words or by conduct — is not in itself a defence in tort. A defendant who reacts to provocation by committing a battery, for example, cannot reduce their liability by pointing to the claimant's provocative behaviour.
The position under the Law Reform (Contributory Negligence) Act 1945 is that the Act permits apportionment of damages where the claimant's fault contributed to their own damage. However, the courts have held that this mechanism does not apply to trespass to the person.
Lane v Holloway
In Lane v Holloway [1968], the Court of Appeal held that provocation by the claimant could not reduce or extinguish the defendant's liability in battery. The defendant, who had struck the claimant in response to an insult, sought to argue that the claimant's provocative conduct should mitigate the damages or provide a partial defence. The court rejected this argument, confirming that provocation has no place as a defence in the law of trespass to the person.
Confirmation of the Current Position
The Court of Appeal definitively confirmed this position in Co-Operative v Pritchard [2011]. The court held that the Law Reform (Contributory Negligence) Act 1945 does not apply to trespass to the person, and that contributory negligence cannot be pleaded as a defence — whether in full or by way of apportionment — to a claim in battery, assault, or false imprisonment. It is important to note the chronological development of the law in this area: historically, courts had at times accepted provocation-based arguments as a means of reducing or denying liability. The decisions in Lane v Holloway [1968] and Co-Operative v Pritchard [2011] have firmly closed the door on that approach, establishing that neither provocation nor contributory negligence provides any defence to trespass to the person in modern English law.