Committees on Bills
A Public or Private Bill Committee is appointed for each Bill that goes through Parliament. Depending on its complexity, the consideration of a Bill can take a few minutes to a few months.
The Lords meet as a whole House in this function (in the debating chamber) or as a Grand Committee away from the chamber. Proceedings in a Grand Committees are the same as Committees of the whole House with an important exception: motions must be passed unanimously, so a dissenting voice from one Member could block an amendment to a Bill.
Naming Public Bill Committees
Each Public Bill Committee is named after the Bill it considers. For example, a committee considering a Bill titled the Climate Bill would be called the Climate Bill Committee.
How they work
Each committee is assigned a chairman and debate Bills as they would do in the Commons chamber, with broadly the same rules of debate applying. Public Bill Committees, unlike the Standing Committees they replace, have the power to take written and oral evidence from officials and experts outside of Parliament. This is intended to give Committee members more information on which to make their decisions.
The minimum number of Members in a committee is 16 and the maximum is about 50. The proportion of Members in a Public Bill Committee mirrors the political parties' strengths in the Commons, so there is always a government majority.
Public Bill Committees examine each Bill line by line. Once a committee has finished looking at a Bill, it reports its conclusions and any amendments made to the Commons, where Members debate the Bill further.
The Bill is printed again with the amendments made by the Public Bill Committee; this is publicly available in printed and online formats.
Although the Lords do not meet in Public Bill Committees, they have a report stage to allow further consideration of Bills.
Second Reading Committees
Second Readings of non-controversial Bills can be debated in a committee in the Commons, although this is rare. If a Bill passes through such a committee, its Second Reading and committal motions must still be agreed by the House in the Chamber, but will be decided there without debate.
Other General Committees
Additional General Committees exist to debate matters in specific areas, such as the Scottish Grand Committee, the Welsh Grand Committee, the Northern Ireland Grand Committee; committees on Delegated Legislation and European documents.