1The Federal Assembly shall ensure the maintenance of good relations between the Confederation and the Cantons.
2It shall guarantee the cantonal constitutions.
3It shall decide whether to approve intercantonal agreements and treaties between Cantons and foreign countries where the Federal Council or a Canton raises an objection to any such treaty.
Article 172 of the Federal Constitution regulates three important tasks of the Federal Assembly (National Council and Council of States) in Swiss federalism.
Fostering relations between the Confederation and the cantons: The Federal Assembly ensures that the Confederation and cantons work well together. It consults the cantons on important legislation and takes their interests into account. For example, parliamentary committees regularly hold discussions with cantonal representatives before new federal legislation is adopted.
Guaranteeing cantonal constitutions: Every new cantonal constitution must be approved by the Federal Assembly. It examines whether the constitution complies with federal law and respects fundamental rights. Without this approval, a cantonal constitution cannot enter into force. Example: If a canton were to amend its constitution in a way that restricted freedom of expression, the Federal Assembly would have to reject this amendment.
Approval of treaties between cantons: Cantons may conclude treaties among themselves (called concordats). They may also conclude treaties with foreign countries. The Federal Assembly need only approve these if the Federal Council or another canton objects to them. A well-known example is the HarmoS Concordat, which harmonises schooling in various cantons.
These provisions ensure that Swiss federalism functions and that all levels of government are respected.
N. 1 Art. 172 FC combines various competences of the Federal Assembly within the federal system of relationships. The provision stems from Art. 85 no. 5, 6 and 7 of the former FC. In the constitutional reform of 1999, these competences were adopted unchanged but systematically consolidated into one article (FG 1997 I 1, 410 f.). The Dispatch emphasises the role of the Federal Assembly as "guardian of the federal order" and its mediating function between the Confederation and the cantons (FG 1997 I 411).
N. 2 The historical roots reach back to the Federal Constitution of 1848. Even then, the guarantee of cantonal constitutions was a central federal competence to ensure homogeneity of the constitutional order in the cantons. The approval of intercantonal treaties served to safeguard federal interests in horizontal cooperation between the cantons.
N. 3 Art. 172 FC is located in Section 3 of Chapter 5 on the competences of the Federal Assembly. The norm concretises the general supervisory function of the Federal Assembly (→ Art. 169 FC) in the federal context. It complements Art. 186 para. 4 FC, which assigns the Federal Council the task of maintaining relations with the cantons.
N. 4 The guarantee competence under para. 2 is closely connected with Art. 51 FC (cantonal constitutions), which establishes the material requirements for cantonal constitutions. The approval competence under para. 3 concretises Art. 48 FC (treaties between cantons) and Art. 56 FC (relations of the cantons with foreign countries).
N. 5 "Maintaining relations" encompasses all measures to promote cooperative federalism. This includes regular consultations, the involvement of cantons in federal legislation (→ Art. 45 FC) and the consideration of cantonal interests in federal decisions. The Federal Assembly fulfils this task particularly through its committees, which regularly conduct hearings with cantonal representatives.
N. 6 The provision establishes an institutional guarantee of federalism, but no enforceable rights of the cantons. It obliges the Federal Assembly to adopt a federalism-friendly basic attitude in the exercise of all its competences.
Para. 2: Guarantee of cantonal constitutions
N. 7 The guarantee is a preventive control procedure. The Federal Assembly examines whether the cantonal constitution complies with federal law (Art. 51 para. 1 FC), guarantees political rights (Art. 51 para. 1 FC) and has been adopted by the people (Art. 51 para. 1 FC). The procedure is regulated in Art. 12 ParlA.
N. 8 The guarantee is granted by simple federal decree (Art. 163 para. 2 FC). It may be granted in full, partially or subject to conditions. If the guarantee is refused, the canton must adapt the objected provisions.
Para. 3: Approval of intercantonal and international treaties of the cantons
N. 9 The approval requirement only applies if the Federal Council or a canton raises an objection. This is an expression of cooperative federalism: In principle, the cantons are free in their treaty-making activities, and federal control only intervenes subsidiarily.
N. 10 Both treaties between cantons (concordats) and treaties of cantons with foreign countries are subject to approval. Mere administrative agreements without normative character or private law contracts are not covered.
N. 11 The guarantee under para. 2 has constitutive effect: Without guarantee, a cantonal constitution cannot enter into force. Guaranteed constitutional provisions enjoy special protection from judicial review. The Federal Supreme Court generally does not exercise abstract or incidental judicial review (BGE 145 I 259 E. 5.1; BGE 138 I 378 E. 5.4.2).
N. 12 However, this restraint has exceptions: In case of a development of federal law since the guarantee, the Federal Supreme Court may examine in the concrete case whether the cantonal constitutional provision is still compatible with superior law (BGE 140 I 394 E. 3.3).
N. 13 The refusal of approval under para. 3 leads to the nullity of the treaty. The cantons must adapt the treaty or forego its conclusion.
N. 14 In doctrine, there is disagreement about how far judicial restraint regarding guaranteed cantonal constitutions should reach. Häfelin/Haller/Keller/Thurnherr (Bundesstaatsrecht, 10th ed. 2020, N 1823) advocate a strict position: The Federal Supreme Court should only review guaranteed provisions in cases of obvious violations of mandatory international law. Ehrenzeller/Schweizer (St. Galler Kommentar BV, Art. 172 N 15) argue for a more differentiated approach taking into account the hierarchy of norms and the democratic principle.
N. 15 The scope of the approval requirement under para. 3 is also controversially discussed. While Waldmann (BSK BV, Art. 172 N 22) advocates a broad interpretation that covers all treaties with normative character, Tschannen (Staatsrecht, 4th ed. 2021, § 23 N 15) limits the requirement to treaties of considerable political or legal significance.
N. 16 For the total revision of a cantonal constitution, early consultation with the federal authorities is recommended to avoid obstacles to guarantee. The State Policy Committees of both chambers offer informal preliminary clarifications.
N. 17 For intercantonal treaties, the following applies: The objection period for the Federal Council and cantons is three months from notification (Art. 62 GBOA). In practice, objections are rarely raised. Nevertheless, the cantons should notify the Federal Council of important concordats early to avoid legal uncertainties.
N. 18 Maintaining federal relations under para. 1 requires an active role from the Federal Assembly. Parliamentary motions on cantonal concerns should be taken seriously and the cantons should be involved in important legislative projects beyond the formal consultation procedure (→ Art. 45 FC).
BGE 138 I 378 of 3 July 2012
Powers of review of the Federal Supreme Court after guarantee of a cantonal constitution by the Federal Assembly. Review of a cantonal constitution is in principle not subject to Federal Supreme Court control insofar as it is guaranteed.
«According to consistent Federal Supreme Court case law, a cantonal constitution guaranteed by the Federal Assembly (Art. 51 para. 2 and Art. 172 para. 2 Federal Constitution) is therefore not subject to Federal Supreme Court control insofar as it provides a sufficient basis in the guaranteed provisions for the disputed state activity.»
BGE 140 I 394 of 1 January 2014
Power of the Federal Supreme Court to review cantonal constitutional provisions in specific cases. Development of constitutional law since the guarantee may lead to review.
«The principle of electoral equality flowing from Art. 34 Federal Constitution has been further developed since the guarantee of the constitution of the Canton of Appenzell A.Rh. by the Federal Assembly in 1996. This development must be taken into account, which is why the Federal Supreme Court, following an appeal concerning the 2011 election of the Cantonal Council of Appenzell A.Rh., examines whether the electoral procedure regulated in its basic features in the cantonal constitution is compatible with electoral equality.»
BGE 145 I 259 of 29 July 2019
Requirements for the review of provisions of a cantonal constitution by the Federal Supreme Court. Fundamental waiver of abstract and incidental control of guaranteed cantonal constitutions.
«According to long-standing practice, the Federal Supreme Court refrains not only from abstract norm control, but in principle also from incidental control of provisions of cantonal constitutions in view of their guarantee by the Federal Assembly (cf. Art. 51 para. 2 Federal Constitution).»
BGE 118 IA 124 of 1 January 1992
Review of cantonal constitutional provisions in abstract norm control proceedings. Amendments to cantonal constitutions cannot be challenged by constitutional appeal.
«Amendments to cantonal constitutions cannot be challenged by constitutional appeal in abstract norm control proceedings; they are subject exclusively to the guarantee of the Federal Assembly.»
Judgment 1P.285/2005 of 8 June 2005
Cantonal bodies are entitled, but not obliged, to review the constitutional admissibility of initiatives. The guarantee also relates to the initiative procedure.
«The Federal Supreme Court has held in connection with the right of initiative that the competent cantonal bodies are entitled, but not obliged, from the perspective of the federal legal guarantee of voting rights to review initiatives for their substantive lawfulness and compatibility with norms of higher order.»
BGE 96 I 636 of 8 December 1970
Interpretation of concordats and conclusion of intercantonal treaties through conclusive acts. No automatic creation of concordats through identical constitutional provisions.
«An intercantonal treaty can in principle be concluded through conclusive acts. However, identical constitutional provisions in different cantons do not without more establish an intercantonal treaty that would be withdrawn from termination by the cantons.»
BGE 96 I 210 of 16 September 1970
Concept of concordat as distinct from simple treaties with other cantons. Treaties referendum for intercantonal agreements to strengthen police security measures.
«A concordat is an intercantonal agreement. In practice, however, not all intercantonal treaties are designated as concordats. The Thurgau cantonal constitution distinguishes between 'concordats', which are subject to popular vote, and 'treaties with other cantons', which the Grand Council can approve on its own authority.»
BGE 112 IA 75 of 21 March 1986
Exemption of an extra-cantonal religious institution from inheritance tax based on a reciprocity declaration. Questions of competence in the conclusion of concordats.
«Under what circumstances can a canton invoke that the authority acting for it was not competent to conclude a concordat or to issue a reciprocity declaration? Assessment of this question according to customary international law.»
BGE 97 I 241 of 5 May 1971
Intercantonal land improvement enterprise under the Agriculture Act. Delimitation between formal intercantonal state treaties and mere understandings among cantonal governments.
«Is an understanding among cantonal governments sufficient for the establishment of an intercantonal land improvement enterprise or does this require a formal intercantonal state treaty?»