Duress of Circumstances

CPS guidance on mental health and defendants situates duress of circumstances alongside duress by threats as a single common law defence subject to the same core exclusion: "duress is a common law defence to all crimes except murder, attempted murder and treason involving the death of the sovereign", citing R v Gotts [1992] 2 AC 412. The guidance treats the two variants - a specific threat from an identifiable person, and a wider set of compelling external circumstances - as raising the same underlying legal question, describing the test as asking whether "a threat or circumstances compelled a person to act as they did", which shows CPS guidance draws no distinction in principle between the two forms of the defence once it comes to assessing whether the defendant was justified in breaking the law.

The test the tribunal applies is objective rather than a simple inquiry into the defendant's own state of mind: prosecutors must ask "would the threat or circumstances have had that effect on a person of reasonable firmness?" - that is, whether a hypothetical person of reasonable firmness, sharing the defendant's relevant characteristics, would have felt compelled to act as the defendant did. CPS guidance notes one narrow exception to that objective standard: a jury may take into account whether the defendant's own mental health made them more susceptible to the compelling threat or circumstances, but only where there is expert evidence of a genuinely 'recognised condition' - mere assertion of increased vulnerability, without medical evidence meeting that threshold, does not lower the reasonable-firmness standard.