Re Parliamentary Privileges Act 1770 (The Strauss Case) [1958] AC 331; (1958) 21 MLR 456

Key point

  • The freedom of speech of Members of Parliament is protected by the Bill of Rights, as long as they act in the context of ‘proceedings in parliament’


  • Bill of Rights 1688 Art. 9:  “The freedom of speech and debates or proceedings in Parliament ought not to be impeached or questioned in any court or place out of Parliament”
  • An MP had sent a letter to a minister, making allegations against the company British Electricity 
  • The London Electricity Board threatened to sue the MP in libel by calling attention to the Parliamentary Privilege Act 1770, which says that any person may prosecute an action or suit in any court against any person, even if they may be entitled to the privilege of Parliament, i.e. MPs
  • This was considered a possible breach of the privilege of Parliament and the opinion of the Judicial Committee of the Privy Council was sought

Held (Privy Council)

  • The Parliamentary Privileges Act 1770 could not be used to threaten Members of Parliament for actions/positions taken during ‘proceedings of Parliament’, as per article 9 Bill of Rights

Viscount Simmonds

  • If read literally, the 1770 Act would ‘repeal the ninth article of the Bill of Rights’, a conclusion, which ‘cannot lightly be reached’: p. 350
  • In order for the 1770 Act to be compatible with the Bill of Rights, it’s meaning had to be limited to proceedings against Members of Parliament in respect of their ‘debts and actions as individuals’, and not of their conduct in Parliament as Members of Parliament: p. 350
  • The ancient and important ability of MPs ‘to speak without fear or favour in Parliament’ must be protected: p. 350
  • Treating ‘the issue of a writ against a Member of Parliament in respect of a speech or proceeding by him in Parliament as a breach of its privileges’, would thus not be contrary to the 1770 Act and perfectly proper: p. 352
  • The council did not discuss if the letter was a ‘proceeding in parliament’, a conclusion to which the parliamentary committee of privileges came by itself: p.348


  • Lord Denning disagreed (“The Strauss Case” [1985] Public Law 80), arguing for a wider interpretation of the 1770 act 
  • He interprets the act to entitle anyone to bring an action against an MP without it being impeached under any privilege, reading the 1770 act literally 
  • The House of commons is not entitled to find a breach of privilege, with Denning reserving this right for the courts
  • ‘An action for defamation would not succeed because of the provision in Article 9 when it reached the courts, but the House’s punitive power to prevent the issue of a writ against members had been removed by the 1770 legislation’: Parliamentary Privilege- Minutes of Evidence, Memorandum by Dr Geoffrey Marshall, Provost, The Queen’s College, Oxford, April 1999