Amendments to the Constitution of Ireland are only possible by way of referendum. A proposal to amend the Constitution of Ireland must be initiated as a bill in Dáil Éireann, be passed by both Houses of the Oireachtas (parliament), then submitted to a referendum, and finally signed into law by the president of Ireland. Since the constitution entered into force on 29 December 1937, there have been 32 amendments to the constitution.

Aside from amendments to the Constitution itself, the Constitution also provides for referendums on ordinary bills; this is known as an ordinary referendum. This provision has never been used.

Procedure for amendment of the Constitution Referendum The procedure for amending the constitution is specified in Article 46. A proposed amendment must take the form of a bill to amend the constitution initiated in Dáil Éireann, the house of representatives of the Oireachtas. It must then be passed or deemed to have been passed by both Houses of the Oireachtas. The Third Amendment of the Constitution Bill 1958, a proposal to alter the voting system, did not pass the Seanad but was deemed to have passed the Seanad 90 days after it was sent by the Dáil. After passage through the Houses of the Oireachtas, the Minister for Housing, Local Government and Heritage must set a date for the referendum not less than thirty days and not more than ninety days after the date of the order.

The Electoral Commission has functions to give a general explanation of the subject matter and text of the referendum and promote public awareness of the referendum and encourage the public to vote. From 1998 to 2023, these functions were previously carried out by a Referendum Commission established for each referendum.

A simple majority of votes cast is sufficient to carry an amendment, with no minimum turnout required for a constitutional referendum to be considered valid. The vote is conducted by secret ballot. A proposal to amend the constitution put to a referendum must not contain any other proposal. While British citizens resident in the state may vote in a general election, only Irish citizens can participate in a referendum.

After the referendum Once the referendum count has concluded the referendum returning officer signs a provisional referendum certificate, and publishes a copy in . Anyone wishing to challenge the results of the referendum then has seven days to apply to the High Court for leave to present a referendum petition. If no one makes such an application, if leave is not granted, or if a petition is dismissed, the referendum certificate becomes final.

When the referendum passed and the final certificate has issued, the amendment must be signed into law by the President "forthwith".Article 46 of the Constitution of Ireland. Provided that the correct procedure has been complied with, the President cannot veto an amendment. The dates given for the amendments listed in this article are, unless otherwise stated, the dates on which they were signed into law. The shortest gap between the referendum and signing into law was twelve days for the 18th, 19th and 20th amendments. The longest was 899 days for the 31st amendment. No referendum has ever been annulled by the courts.

Transitional and conditional amendments The Nineteenth Amendment, passed in May 1998, introduced a novel method of amendment. Its provisions allowed the later amendment to Articles 2 and 3 of the Constitution in 1999. The Nineteenth Amendment did not itself amend those articles, but rather introduced a temporary special mechanism by which the Government could order their amendment once it was satisfied that certain commitments made by other parties to the Good Friday Agreement had been complied with. The sections added to the text of the Constitution which provided for this later amendment to Articles no longer appear in the published official text of the Constitution, in line with their own provisions.

A similar method would have been used with the Twenty-fifth Amendment of the Constitution Bill 2001 to restrict abortion, which was rejected. The proposed Thirty-second Amendment of the Constitution Bill 2013 to abolish Seanad Éireann involved later amendments which would have taken effect after the next general election.

The Thirty-third Amendment that established the Court of Appeal had amendments which became part of the text only on the later establishment of the Court, and transitory provisions which would not appear in later printed official versions.

Historical methods As a transitional measure, for the first three years after the election of the first President of Ireland a bill to amend the Constitution could be passed by the Oireachtas as an ordinary act. An amendment bill the election of the first President (on 25 June 1938) have required a referendum. To prevent the Oireachtas abusing this provision, the President had the power to refer such a bill to the people. The First and Second Amendments were adopted in this way; President Douglas Hyde chose to sign each into law without referendum. The three-year limit was entrenched to prevent it being extended without referendum. Since 25 June 1941, the third anniversary of President Hyde's election, every amendment has had to be put to a referendum after its passage through the Oireachtas.

List of amendments and referendums The following table lists all amendments to the Constitution, and all past referendums relating to the Constitution. In general it does not list proposed amendments which were not passed by the Oireachtas, for which see the separate list of failed amendments to the Constitution of Ireland. The exception is the 2001 Twenty-second Amendment Bill, listed below to explain the gap in the numbering of subsequent amendments.

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