Article 118 [Constitutional Revision]
At any time, the Federal Constitution may be revised wholly or in part.

Article 119 [Constitutional Total Revision]
The total revision shall be carried out in accordance with the forms laid down for federal legislation.

Article 120 [Constitutional Total Revision Procedures]
(1) If one section of the Federal Assembly decides on a total revision of the Federal Constitution and the other does not consent or if 100,000 Swiss citizens entitled to vote demand the total revision of the Federal Constitution, the question whether such a revision should take place or not must be submitted in both cases to the vote of the Swiss people.

(2) If in either of these cases the majority of the Swiss citizens casting a vote give an affirmative answer, both Councils shall be elected anew in order to undertake the revision.

Article 121 [Constitutional Partial Revision Procedures]
(1) Partial revision may be carried out either by means of a popular initiative or in accordance with the forms laid down or federal legislation.

(2) The popular initiative consists of a request, presented by a hundred thousand Swiss citizens entitled to vote, aiming at the introduction, setting aside or modification of specified articles of the Federal Constitution.

(3) If by means of a popular initiative several different provisions are to be modified or introduced into the Federal Constitution, each one must be the subject of a separate initiative request.

(4) An initiative request may consist of a general proposal or take the form of a complete draft.

(5) If such a request consists of a general proposal and if it meets with the approval of the Federal Chambers, the latter shall prepare a partial revision along the lines of the proposal and submit their draft to the people and the Cantons for adoption or rejection. If the Federal Chambers do not approve of the request, the question of partial revision shall be submitted to the decision of the people; if the majority of the Swiss citizens casting a vote decide in the affirmative, the Federal Assembly shall undertake the revision in conformity with the decision of the people.

(6) If the request is in the form of a complete draft and if it meets with the approval of the Federal Assembly, the draft shall be submitted to the people and the Cantons for adoption or rejection. If the Federal Assembly disagrees, it may prepare its own draft or recommend the rejection of the proposed draft and submit its own draft or recommendation of rejection together with the draft proposed by the initiative to the decision of the people and the Cantons.

Article 121 A [Constitutional Alternative Revision Procedures]

(1) If the Federal Assembly draws up a counter-draft, three questions shall be submitted to the voters on the same ballot paper. Every voter can state unreservedly

(2) The absolute majority shall be determined for each question separately. Unanswered questions shall not count.

(3) If both the popular initiative and the counter-draft are accepted, the result of the third question shall decide the issue. The text which obtains more of the people's and Cantons' votes on this question shall come into force. If, on the other hand, one text obtains more of the people's votes and the other more of the Cantons' votes, then neither of the texts shall come into force.

Article 122 [Popular Initiative Procedures]
A federal law shall determine the procedure to be followed in the case of popular initiative requests and votes on the revision of the Federal Constitution.

Article 123 [Constitutional Revision Approval]
(1) The revised Federal Constitution or the revised part of it, as the case may be, shall enter into force if it has been approved by the majority of the Swiss citizens casting a vote and the majority of the Cantons.

(2) In order to determine the majority of the Cantons, the vote or each Half-Canton is counted as half a vote.

(3) The result of the popular vote in each canton is considered to be the vote of that Canton.