The committees perform an important role in the process of exercising the Sejm's controlling function. Each of the committees is vested with special powers described in the Standing Orders of the Sejm, according to which the committees examine the reports and information provided by ministers, heads of supreme organs of the State administration and heads of other State offices and institutions. The committees are also competent to analyse the activities of particular departments of the administration and the State economy. The Standing Orders of the Sejm oblige all ministers and other State officials to present reports and supply information at the request of a committee presidium as well as to participate in the sittings of the committees whenever the subject of the debate coincides with matters which lie within the competence of that minister or official. According to the Standing Orders, the presidium of a committee or its chairman may invite persons other than officials of State administration for the purpose of presenting information and explanations on issues which are the subject of a particular debate or committee investigation. Such a solution may be applied whenever the committee exceeds the limits of controlling the executive power in the narrow meaning.

Extensive possibilities to conduct the committees' controlling activities are provided for in the Act on the Exercise of the Mandate of a Deputy or Senator. Art. 16 par. 2 of the aforementioned law declares that control may be exercised over matters which form the subject of a particular committee's activity. Practice will tell whether the realisation of control entails other subjects than those enlisted in the Constitution. It should be stressed that the Act grants the Sejm committees the right to demand information and explanations from the organs and institutions of the self-government (that is, not only from the local self-government), social organisations, State-owned and self-government-owned enterprises and establishments, commercial companies with the participation of State and communal legal persons.

The forms of the controlling activities of the committees are also regulated by the provisions of the Standing Orders of the Sejm which provide them with the right to inspect and examine the performance of enterprises and companies with State Treasury participation, as well as other enterprises and governmental institutions. The information so gathered may be used for the formulation of opinions and the undertaking of particular actions which the committees will deem necessary and which will remain in conformity to the Constitution, the statutes and the Standing Orders of the Sejm.

The aforementioned actions may consist in submitting to the Chamber - according to the wording of the Standing Orders - an appropriate draft of a resolution (containing a request directed to a particular organ of the State to perform the action described in the resolution), a declaration (containing an obligation to adopt a particular course of action), an appeal (containing a request to undertake certain actions, to exercise an initiative or perform a particular task), or a statement (containing the position on a particular matter).

A committee has also the possibility to adopt desiderata or opinions. According to the Standing Orders of the Sejm a desideratum contains the committee's postulates regarding particular issues and may be directed to the Council of Ministers or one of its members, the President of the Supreme Chamber of Control, the President of the National Bank of Poland, the Public Prosecutor General and the General Inspector of Labour. The addressee of a desideratum is not obliged to act in accordance with the committee's postulates, although he may decide to do so. On the other hand, the addressee has a duty to respond to a desideratum, that is, present his opinion as to the contents thereof and inform the Marshal of the Sejm about his position in writing no later than 30 days from the day of receiving a desideratum, unless the Marshal orders a different time period on the motion of the addressee and after consulting the committee presidium. The Standing Orders provide the Marshal of the Sejm with important powers as regards the committees' use of desiderata, the latter being an instrument of control and inspiration.

The committee may also take avail of another instrument which bears a slightly different character than desiderata, i.e. it has the possibility to adopt a resolution called opinion. In accordance with the provisions of the Standing Orders of the Sejm, an opinion contains the committee's position on a particular matter. The committee may present an opinion to the same organs which are the addressees of the desiderata, as well as to other central governmental departments and institutions. An opinion serves the purpose of inspiring rather than controlling although the committee may ask the addressee of the opinion to present his view on the issues contained therein.