Most select committees do most of their work through inquiries into topics within their remit. This could be an area of policy, a draft bill, or a response to an event.
Suggestions for inquiry subjects come from many sources, including the chair and committee members, interest groups and members of the public.
Most departmental committees will set a forward programme that still leaves some space for an urgent response to changing events, such as the announcement of new policy by the Government.
The Liaison Committee core tasks is made up of chairs of all the select committees. It takes evidence from the Prime Minister, approves spendig on committee visits and considers issues that impact how committees work. It has agreed core tasks to guide select committees in their work.
For some other committees, the choice of subjects may be determined to a greater extent by external circumstances: the Public Accounts Committee, for example, considers reports produced for it by the National Audit Office.
Some inquiries are very short, with perhaps only a single session of oral evidence and a speedy report. Committees may hold one-off evidence sessions or pursue issues through correspondence or by holding events intending to report at all, but to add to public debate or air an issue of immediate or wide concern (one example is the regular oral evidence session the Liaison Committee holds with the Prime Minister). Other inquiries may last several months and have many evidence sessions.
Oral evidence is not the only way of getting the information needed. All committees seek written evidence, and most use a variety of other methods of gathering information such as surveys, events and online engagement.
Most select committees can set up one sub-committee, a smaller group of Members to do a particular piece of work. Many have the power to meet jointly with other select committees and may carry out joint inquiries into subjects of mutual interest and produce a joint report. They can also invite members of other select committees to attend their meetings and take part in questioning. The Welsh Affairs Committee has the power to meet jointly with any committee of the Welsh Parliament / Senedd Cymru.
Occasionally, select committees are bound tightly by their order of appointment to a narrow remit. The Committee of Privileges, for example, can only consider matters referred to it by the House.