Sometimes a person commits an offence not because anyone forced them, but because the situation itself left no safe lawful option — swerving onto a pavement to avoid a crash, or driving over the limit to escape danger. English law has no single broad defence of "necessity". Instead the idea works mainly through duress of circumstances and a narrow medical necessity doctrine. As a solicitor, you need to know when these defences genuinely apply, when they collapse, and how they sit alongside duress by threats and self-defence — because getting the boundaries right shapes the advice you give and the way a case runs.
What this lesson covers:
- Necessity and Duress of Circumstances — why there is no single defence of necessity, and how duress of circumstances works as a complete acquittal.
- Requirements of the Defence — the threat, the absence of a lawful alternative, the prior fault rule, and what must be present for it to succeed.
- Assessing a Reasonable Response — the two-stage test of proportionality and choosing the lesser of two evils.
- The Murder Exclusion and Burden of Proof — why it can never excuse murder, and who must disprove it.
- Medical Necessity — when a doctor may lawfully treat a patient who cannot consent.
- Distinctions — telling this defence apart from duress by threats and self-defence.