Defences to the Personal Interference Torts
The Nature of Consent
Strictly speaking, the absence of consent is normally considered an element of the torts against the person. This means that the burden of proof is on the claimant to show lack of consent: Freeman v Home Office (No 2)  QB 524.
However, this orthodoxy has been challenged by some judges. For example, Clarke MR argues that the defendant is normally expected to provide evidence that the claimant consented. This makes consent a defence in practice: Ashley v Chief Constable of Sussex Police  1 WLR 398.
When is Consent Valid?
Consent must be ‘real’: Chatterton v Gerson  QB 432. This means that:
The claimant must be informed as to the nature of what the defendant is doing and his intentions in a ‘broad’ sense. Mere failure to inform as to risks or side-effects is insufficient. Bad faith fraud and misrepresentation may vitiate consent: Chatterton v Gerson  QB 432.
The consent must not be obtained by duress. Physical threats will vitiate consent, though more diffuse pressures may not: see Freeman v Home Office (No 2)  QB 524 where institutional pressures on a prisoner did not vitiate his consent to medical treatment.
The consent must not have been revoked. However, for false imprisonment, it appears that the claimant’s withdrawal of consent to detention is invalid if effecting the withdrawal is inconvenient and costly: Herd v Weardale Steel Coke and Coal  AC 67.
Claimants are taken to implicitly consent to any contact which is inherent in the activity they are engaged in. This is particularly relevant in sports and recreational activity, where claimants are taken to consent to any contact which is an ordinary or inherent part of the game or activity: Blake v Galloway  1 WLR 2844.
The claimant must have capacity to consent. They must be able to understand what the act involves, its purpose and consequences. In the case of children, they must also have sufficient life-experience and exposure to different viewpoints, and the capacity to appreciate any moral or family issues that the decision involves: Gillick v West Norfolk and Wisbech HA  AC 112.
It is possible that some actions cannot be consented to under the civil law. This is the case under the criminal law, where a person cannot consent to actual bodily harm or greater: R v Brown  1 AC 212. However, there have been obiter remarks that consent is always a defence in tort if the harm inflicted was proportionate to what the claimant expected: Lane v Holloway  1 QB 379.
Self-Defence & The Defence of Property/Others
Requirements of the Defence
To demonstrate the defence of self-defence or defence of others, the defendant must show that:
- It was necessary to respond to an attack, or imminent attack, on the defendant or another person or property;
- The force used was reasonable; and
- The bar under s 329 of the Criminal Justice Act 2003 is not applicable.
See Ashley v Chief Constable of Sussex Police  1 AC 962.
Whether it is necessary to act is likely judged by reference to the facts which the defendant honestly and reasonably believed, as indicated in Ashley v Chief Constable of Sussex Police  1 AC 962. The defendant can rely on a reasonable belief he was being attacked. He cannot rely on an unreasonable belief even if it is honestly held.
However, in Ashley, Lord Scott speculated obiter that the defendant had to prove that he was actually under attack. If so, it would not be enough that the defendant reasonably (but mistakenly) thought he was under attack.
To be reasonable, the force used should not be out of proportion to the attack or threat: Lane v Holloway  1 QB 379. Less force is expected where the threat is against property rather than a person.
If an attack against the property has not yet begun, the courts expect a verbal warning first: Green v Goddard (1702) 2 Salk 641.
Section 329 of the Criminal Justice Act 2003
An action for assault, battery or false imprisonment cannot be brought without judicial permission if the defendant has been convicted of an indictable criminal offence for the same action: ss 329(1)-(2).
Permission will only be granted if there is evidence that 1) the defendant’s actions were grossly disproportionate in the circumstances (s 329(2)) and 2) the defendant was not acting in self-defence, the defence of others, protecting property or 3) was not acting to arrest the claimant, believing that the claimant was about to commit an offence, was committing an offence or had just committed an offence: s 329(5).
If permission is granted, the defendant has a defence if he can show that his actions were not grossly disproportionate and that:
- He was acting in self-defence, the defence of others, protecting property; or
- He was trying to arrest the claimant, believing that the claimant was about to commit an offence, was committing an offence or had just committed an offence: s 329(4).
Lawful Arrest & Detention
Arrest and Detention by the Police
The police have a defence to the personal torts if they are acting to arrest the claimant for a suspected criminal offence or engaging in a statutory stop-and-search.
Authorities only have a defence if they are acting within the scope of their common law or statutory powers under the Police and Criminal Evidence Act 1984 (or any other relevant statute).
Not all illegalities (such as breaches of procedure) will remove access to the defence unless it takes the officer’s acts completely outside of the ambit of their lawful powers: Hague v Deputy Governor of Parkhurst Prison  1 AC 58. For example, an officer acting in bad faith who knows he has no authority would be acting outside of the scope of his powers. Similarly, if a valid order for detention is withdrawn, there is no longer lawful authority to detain and subsequent action against the claimant is unlawful: R v Governer of Brockhill Prison ex parte Evans  2 AC 19.
Arrest and Detention by the Public
Members of the public have a general power to ‘use such force as is reasonable in the circumstances in the prevention of crime, or in the effecting or assisting in the lawful arrest of offenders or suspected offenders, or of persons unlawfully at large’: Criminal Law Act 1967, s 3. It is limited to indictable offences, however: s 2.