Hearing and evidence (Standing Orders 109 and 110)
46.21Petitions against bills are automatically referred to committees, and the parties may be heard by themselves, their counsel, representatives or parliamentary agents. The proceedings of a Lords committee on a private bill are essentially the same as those of a committee in the Commons (see para 45.7 ), except that the committee itself deals with questions relating to the rights of petitioners to have their petition considered (see para 46.20 ).
Witnesses in opposed proceedings always give evidence on oath, but witnesses in an unopposed bill committee do not, except the witness who formally proves the preamble (see below).
Witnesses may be examined upon the preamble; against particular clauses; or in support of new clauses or amendments. Parties may be similarly heard upon their petitions against alteration in the bill. Witnesses are examined, cross-examined and re-examined. The promoter of the bill must always prove the preamble, that is to say, satisfy the committee about the general expediency of the bill. The usual practice today is for the committee to hear the promoter and petitioners on all the aspects of the bill, including all the clauses which are in contention, and then to decide whether the bill should proceed and what amendments, if any, should be made to it. If the committee decides that the bill should proceed, the preamble is proved formally at the conclusion of proceedings. This is done by a witness for the promoter stating on oath that they have read the preamble to the bill and that it is true.
Unless the Senior Deputy Speaker otherwise directs, every opposed bill on which a select committee has reported that the bill should proceed is re-committed to an unopposed bill committee (see para 46.28 ) for consideration of the unopposed provisions; but no decision made by a select committee may be varied by an unopposed bill committee.