R (Purdy) v Director of Public Prosecutions [2009] UKHL 45

Key point

  • The principle of legality in articles of the ECHR requires any interference with Convention rights to have a legal basis in domestic law, for the law or rule to be accessible and precise, and for the law and rule to be applied in a non-arbitrary and proportionate manner
  • For a law or rule to be accessible and precise, the executive will have ensure that the scope of discretion under the law and the manner of its exercise are indicated with sufficient clarity – this might necessitate the promulgation of office-specific policies by prosecutors identifying the factors they will take into account when exercising prosecutorial discretion


  • P’s husband intended to her travel to Switzerland to attain physician-assisted suicide would be illegal under s.2(1) Suicide Act 1961 with a potential penalty of 14 years
  • P sought information on whether her husband would be prosecuted if he helped her travel to Switzerland, as s.2(4) SA allows the Director of Public Prosecutions to decide when to bring charges under s.2(1)
  • DPP has never exercised his discretion to under s2(4) Suicide Act to prosecute such conduct, but has only ever published his official reasoning for his decision in one previous case
  • P argued that she should be entitled to information on factors the DPP will take into account to exercise his discretion under s2(4) under her article 8 ECHR right to respect for private and family life

Held (House of Lords)

  • Appeal allowed
  • Art.8(2) ECHR places a duty on the DPP to promulgate a policy on the factors it will take into account in deciding whether to prosecute under s.2(4) Suicide Act 1961

Lord Hope of Craighead

Principle of legality under article 8(2)

  • The requirement of article 8(2) that there should be no interference with the right under article 8(1) except such as was in accordance with the law required the court to consider:
    1. whether there was a legal basis in domestic law for any such interference,
    2. whether the law or rule in question is sufficiently accessible to the individual who is affected by the restriction, and sufficiently precise to enable him to understand its scope and foresee the consequences of his actions so that he can regulate his conduct without breaking the law, and
    3. whether the law or rule was being applied in a way which was arbitrary or disproportionate: [40]
  • ‘A law which confers a discretion is not in itself inconsistent with this requirement, provided the scope of the discretion and the manner of its exercise are indicated with sufficient clarity to give the individual protection against interference which is arbitrary’: [41]

Current case

  • The Code for Crown Prosecutors issued by the DPP will ‘normally provide sufficient guidance to Crown Prosecutors and to the public as to how [prosecutorial] decisions should or are likely to be taken’: [53]
  • However, in dealing with prosecution under the s.2(4) Suicide Act 1961, the Code itself does not satisfy the article 8(2) requirements of accessibility and foreseeability: [54]
  • ‘I consider that the offence of aiding and abetting the suicide of another under section 2(1) Suicide Act 1961 is unique in that the critical act – suicide – is not itself unlawful, unlike any other aiding and abetting offence. For that reason, I have decided that many of the factors identified in the Code in favour or against a prosecution do not really apply in this case‘: [50]
  • ’I would therefore allow the appeal and require the Director to promulgate an offence-specific policy identifying the facts and circumstances which he will take into account in deciding, in a case such as that which Ms Purdy’s case exemplifies’: [56]


  • Even after the adoption of guidelines, the blanket ban is not truly mitigated by the uncertain prospect of failure to prosecute; considering the high risks involved—long-term deprivation of liberty, social stigma attached to a criminal conviction and jeopardizing one’s future employability and livelihood—this is an insufficient corrective to the general ban.’: The blanket ban on assisted suicide: between moral paternalism and utilitarian justice, Dr Carmen Draghici, E.H.R.L.R. 2015, 3, 286-297, p.292
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