An ad hoc "Committee to assess EU scrutiny procedures" composed of senior MPs and civil servants was set up on 21 November 2003 by the Speakers' Council of the Finnish Eduskunta in order to evaluate, inter alia,  what measures would be needed for the successful adoption of the mechanism into the Finnish parliamentary system. The conclusions of the Committee were agreed and submitted to the Speakers' Council on 18 February 2005.

The Committee concluded that the subsidiarity mechanism would necessitate the creation of a procedure whereby the Eduskunta, if it wishes, could raise an objection on subsidiarity grounds. The Committee considered that it would be most appropriate for the task of subsidiarity control to be assigned to the Grand Committee. The Grand Committee would normally draw on the inputs of sectoral committees. If the Grand Committee deemed it appropriate to raise an objection on subsidiarity grounds, it would propose this to the plenary session in a report. The ad hoc Committee submitted a draft proposal for amending the Eduskunta Rules of Procedure to this effect. No need for constitutional amendments was foreseen.

The following information was provided by the Eduskunta in its replies to the questionnaire for the 13th Bi-annual Report of COSAC:

The supplementary procedural provisions in the Rules of Procedure of the Eduskunta and in the Rules of Procedure of the Grand Committee were sufficient. These amendments regulate the passerelle procedure; introduce standing orders and reporting requirement for Parliament's representatives at Conventions; and the procedures for the examination of conformity with the subsidiarity principle ex-ante and ex post. Detailed procedural provisions concerning subsidiarity control were added to the Rules of Procedure of the Grand Committee.

The provisions concerning national Parliaments in the Treaty of Lisbon do not affect relations between the Eduskunta and the Government or the national preparation of EU matters. It is considered that the Treaty of Lisbon provisions regarding new powers of national Parliaments are supplementary to the Finnish national system. The principle of subsidiarity is understood narrowly and juridically, i.e., it is confined to the questions regulated in Art 5 of the EU Treaty. The procedure is limited to the question of the appropriate decision-making level and does not deal with the goals or content of the proposal. The assessment is that the supervision of the subsidiarity principle will not be of great significance to the activities of the Eduskunta (SuVL 2/2008 vp).

The primary channel of influence for the Eduskunta will continue to be sections 96 and 97 of the Finnish Constitution. The main scope of the functions of the Grand Committee is the formulation of Finland’s national positions and the general supervision of the Government's effectiveness in representing Finnish interests in the European Union (SuVL 2/2008 vp; SuVM 1/2009 vp).

According to the new provisions, the proposals are not automatically examined in terms of the subsidiarity principle – the examination only takes place if someone proposes an examination and the proposal gets sufficient support. The Eduskunta’s EU Secretariat monitors compliance with the subsidiarity principle of the legislative proposals and reports its findings to the Grand Committee. The EU Secretariat delivers the subsidiarity documents to (1) the Members of the Grand Committee, (2) the appropriate sectoral committees and (3) to the regional parliament of Åland in electronic form with notice that any proposal that the Grand Committee examines the matter in terms of subsidiarity must be made within six weeks. A sectoral committee (or the Åland provincial Parliament) may, by a majority decision request the Grand Committee to examine whether or not the subsidiarity principle has been violated; if there is no majority support for this, the matter is terminated without further action.

The Rules of Procedure of the Grand Committee provide a six week limit for proposing that the Grand Committee examines the conformity of proposals with the subsidiarity principle. This leaves at least two weeks for the Grand Committee to examine the matter of subsidiarity and to contact the Government. (Two weeks are deemed to be sufficient for examining the issues mentioned in Art 5 TEU.) Subsidiarity procedures automatically expire if eight weeks have lapsed without the Eduskunta issuing a reasoned opinion.

When a Grand Committee Member or the sectoral committee concerned proposes a subsidiarity examination, the Grand Committee decides by a majority decision whether to carry it out. The examination is automatically carried out if proposed by the Åland regional Assembly. The Grand Committee prepares its report after having heard the Government. The Grand Committee report either concludes that there is no subsidiarity problem or it contains the draft text of a reasoned opinion to the EU Institutions. The final decision is made in the plenary by a simple majority vote. If the Eduskunta approves the draft reasoned opinion, this, together with the Grand Committee report, is sent to the EU Institutions. If the Eduskunta finds that there is no breach of the subsidiarity principle, the decision and Grand Committee report are sent to the EU Institutions for information.

The Parliament of Finland may decide to oblige the Government to take annulment proceedings in the Court of Justice because a legal act is in breach of the subsidiarity principle. The Grand Committee may initiate an examination of this issue on its own, ending in a report and recommendation to the plenary session. If it finds a breach of subsidiarity, it may instruct the Government to take action in the Court of Justice.

In both the ex ante and ex post procedures, the Grand Committee will consult with the Government as a matter of course. In the Finnish constitutional understanding, the Eduskunta has ultimate control over policy, and the Government is obliged to act according to the wishes of the Eduskunta. It would be inconceivable for the Finnish Government to express different opinions than the Eduskunta on any EU issue.