R v Anderson [1986] AC 27, [1985] Crim. L.R. 651

Key point

  • The mens rea for conspiracy does not require the defendants to intend that their agreement actually be carried out (overruled in Yip)


  • Anderson (D) was convicted of conspiring with others to effect escape of X a prisoner contrary to s1 Criminal Law Act 1977
  • In the plot, D was to purchase and supply diamond wire capable of cutting through metal bars, but was injured in an accident and unable to supply wire
  • D argued that the mens rea for conspiracy required each conspirator to not only agree to a course of conduct that will involve the commission of an offence if carried out, but also intend that the offence be committed, D claimed that he did not intend the plan to come into effect or believe that it could succeed

Held (House of Lords)

  • Appeal dismissed – conspiracy may be committed even where the conspirators do not intend for the agreed course of conduct to be carried out

Lord Bridge

Policy justification

  • Minor conspirators should not escape liability: ‘In these days of highly organised crime the most serious statutory conspiracies will frequently involve an elaborate and complex agreed course of conduct in which many will consent to play necessary but subordinate roles, not involving them in any direct participation in the commission of the offence or offences at the centre of the conspiracy. Parliament cannot have intended that such parties should escape conviction of conspiracy on the basis that it cannot be proved against them that they intended that the relevant offence or offences should be committed.’

On the mens rea of conspiracy

  • ‘the necessary mens rea of the crime is, in my opinion, established if, and only if, it is shown that the accused, when he entered into the agreement, intended to play some part in the agreed course of conduct in furtherance of the criminal purpose which the agreed course of conduct was intended to achieve. Nothing less will suffice; nothing more is required.


  • Privy Council in Yip Chiu Cheung held that it did have to be shown that every alleged conspirator intended the agreement to be carried out
  • This decision was criticised by Prof J. Herring:
    • It was true that Anderson did not think that the plot had much chance of success and that he was just in the plan for money, but neither precludes intention, which does not require motive and it is possible to intend a result without thinking one is likely to achieve it
    • Applying Lord Bridge’s logic, it could be said that the parties conspired to commit a crime even if none of them intended it to be carried out
    • Intent to play some part in the agreed course of conduct is a novel suggestion, the key element of a conspiracy is an agreement, not the carrying out of the plan, it will also lead to difficulty in determining what could be said to constitute carrying out an element of the plan
Inchoate Liability Cases
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