Oral evidence

38.36Committees normally take evidence while sitting in public. Evidence may also be taken in private session. When taking evidence, Members sit around a horse-shoe shaped table with the witnesses at a separate table at the open end facing the Chair. Questions may be asked by any member of the committee and the order and allocation of the questioning is directed by the Chair. Where appropriate and with the prior approval of the committee, witnesses may make use of projectors or other visual aids.1 Evidence has on occasion been taken by video link. The Committee Office produces a Guide for Witnesses giving written or oral evidence to a House of Commons select committee which contains information and advice on what to expect and how they should conduct themselves.2 The degree of formality in the questioning of committees depends on the terms of reference of the committee and the subject-matter of the questioning. However, committees, being extensions of the House, possess substantial powers to require answers to questions.3

Evidence may be given in Welsh, with both the Welsh and English versions published in the official record;4 it can also be given in other languages via an interpreter, with the interpretation into English forming the transcribed text and formal record of evidence.

Witnesses are bound to answer all questions which the committee sees fit to put to them,5 and cannot excuse themselves, for example, on the ground that they may thereby subject themselves to a civil action,6 or that they have taken an oath not to disclose the matter about which they are required to testify,7 or that the matter was a privileged communication, as where a solicitor is called upon to disclose the secrets of a client;8 or on the ground that they are advised by counsel that they cannot do so without incurring the risk of self-incrimination9 or exposure to a civil suit,10 or that it would prejudice them as defendant in litigation which is pending,11 some of which would be sufficient grounds of excuse in a court of law. Nor can a witness refuse to produce documents in their possession on the ground that, though in their possession, they are under the control of a client who has given instructions not to disclose them without express authority.12 (For the treatment of matters sub judice, see paras 21.19, 38.25.)

However, a witness who is unwilling to answer a question, after stating their reasons, may ask the Chair either to be excused from answering or to answer in private. Where evidence is taken in private, a witness may also request that the whole or part of their evidence should not be published (see para 38.40 ).

It is generally the case that members of select committees co-operate with the Chair and with each other in questioning witnesses in order more effectively to achieve the purposes for which the committee was appointed by the House. Thus a member of a committee seldom interrupts another member except to obtain elucidation of the question being asked or to contribute to the questioning. However, a question put to a witness may be objected to by a member.13

If a question should be objected to, or if any difference should arise in regard to the questioning of a witness, witnesses and any members of the public who are present are directed by the Chair to withdraw, and the committee proceeds to consider the matter.14 When the committee has come to a decision, the witness is again called in, and the questioning proceeds.15


  1. 1. For example, Environment Committee, Session 1993–94, Minutes of Evidence, HC 366-II, pp 42–53.
  2. 2. The Guide (February 2016) can be found on the parliamentary website (www.parliament.uk ).
  3. 3. See also para 15.5. These powers have been confirmed from time to time. In 1947, the House of Commons resolved ‘that the refusal of a witness before a select committee to answer any question which may be put to him is a contempt of the House and an infraction of the undoubted right of this House to conduct any inquiry which may be necessary in the public interest’, CJ (1946–47) 378. See also Privileges Committee Report, Session 1946–47, HC 138.
  4. 4. Votes and Proceedings, 1 March 2017; see for example Welsh Affairs Committee, Session 2017–19, 18 December 2018, HC 1207.
  5. 5. CJ (1946–47) 378; and see para 15.5.
  6. 6. Parliamentary Oath (Mr Bradlaugh) Committee, Session 1880, HC 226, p vi.
  7. 7. Parl Deb (1823) 9, cc 113, 119, 120, 493.
  8. 8. Parl Deb (1828) 18, c 968 ff.
  9. 9. See First Special Report from the Social Security Committee of Session 1991–92, HC 353.
  10. 10. Parl Deb (1806) 6, cc 353–59.
  11. 11. Loans to Foreign States Committee of Session 1875, HC 367, p liii.
  12. 12. British South Africa Committee of Session 1897, HC 311, p 473.
  13. 13. See Third Report of the Procedure Committee of Session 1997–98, HC 990.
  14. 14. Formally the direction to withdraw follows the agreement of the Committee to a motion to that effect.
  15. 15. For example, Committee on the Official Secrets Acts, Session 1937–38, Minutes of Proceedings, HC 173, p xlv; Foreign Affairs Committee, Session 1997–98, Minutes of Proceedings, HC 1192, pp xxiv–xxv and xxvii.