General Defences

Introduction

This chapter examines the first group of **general defences** in English criminal law: **self-defence**, **duress by threats**, **duress of circumstances** and **necessity**. Each is a **complete defence** — if successful it leads to an **acquittal** of the offence charged, in contrast to the **partial defences** (loss of control and diminished responsibility) which apply only to murder and reduce it to voluntary manslaughter. You must master the **two-stage test for self-defence** under **s. 76 of the Criminal Justice and Immigration Act 2008**, the special **householder rule** in **s. 76(5A)**, the **Graham/Hasan test** for duress, and the very narrow scope of **necessity**.

Assessment focus

For the SQE1 FLK2 assessment, general defences are a high-yield, heavily examined topic. Questions are **single best answer questions (SBAQs)** set in **realistic client-based scenarios**: you will be given a fact pattern and asked whether a defence will succeed or fail, and **why**. The examiner's favourite traps are (i) applying an **objective** test to the **subjective** first stage of self-defence; (ii) applying the **householder** (grossly-disproportionate) test to **non-householder** facts; (iii) overlooking the **Hasan voluntary-association exclusion** in duress; and (iv) confusing **duress by threats** (human demand) with **duress of circumstances** (threat from surrounding circumstances). This is a closed-book assessment — you must be able to recall each test and its leading authorities from memory, and **apply** them rather than simply recite them.

Study tips

1) For self-defence, work the test **mechanically**: was force **honestly** believed necessary (subjective; even an unreasonable mistake counts, unless caused by **voluntary intoxication** — s. 76(5)), then was the force **reasonable** in the circumstances as D believed them (objective). 2) Remember **there is no duty to retreat** and **pre-emptive strikes are permitted** (Beckford). 3) For **householder cases (s. 76(5A))**, the threshold rises to **grossly disproportionate** — but Collins confirms this is **not a blanket licence**. 4) Learn the **five Hasan limits**, especially the **voluntary-association exclusion**; the belief in the threat must be **reasonable**, not merely honest. 5) **Duress is never available on murder, attempted murder or (probably) treason**; **necessity does not justify murder** (Dudley and Stephens) save in the very narrow exception of **Re A (Conjoined Twins)**.