The following are the relevant provisions of Articles 27 and 47 of the Constitution.

Article 27 deals with the reference of Bills to the people and Section 1 says: A majority of the members of Seanad Eireann and not less than one-third of the members of Dail Eireann may by a joint petition addressed to the President by them under this Article request the President to decline to sign and promulgate as a law any Bill to which this article applies on the ground that the Bill contains a proposal of such national importance that the will of the people thereon ought to be ascertained.

Section 4 says: Upon receipt of a petition addressed to him under this Article, the President shall forthwith consider such petition and shall, after consultation with the Council of State, pronounce his decision thereon not later than ten days after the date on which the Bill to which such petition relates shall have been deemed to have been passed by both Houses of the Oireachtas.

Section 5 says: In every case in which the President decides that a Bill the subject of a petition under this Article contains a proposal of such national importance that the will of the people thereon ought to be ascertained, he shall inform the Taoiseach and the Chairman of each House of the Oireachtas accordingly in writing under his hand and Seal and shall decline to sign and promulgate such Bill as law unless and until the proposal shall have been approved either

i. by the people at a Referendum in accordance with the provisions of section 2 of Article 47 of this Constitution within a period of eighteen months from the date of the President's decision, or

ii. by a resolution of Dail Eireann passed within the said period after a dissolution and reassembly of Dail Eireann.

Article 47 deals with the holding of referendums and Section 2. sub-section 1 states: Every proposal, other than a proposal to amend the Constitution, which is submitted by Referendum to the decision of the people shall be held to have been vetoed by the people if a majority of the votes cast at such Referendum shall have been cast against its enactment into law and if the votes so cast against its enactment into law shall have amounted to not less than thirty-three and one-third per cent of the voters on the register.

Section 2. sub-section 2 states: Every proposal, other than a proposal to amend the Constitution, which is submitted by Referendum to the decision of the people shall for the purposes of Article 27 hereof be held to have been approved by the people unless vetoed by them in accordance with the provisions of the forgoing subsection of this section.