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.
When the referendum passed and the final certificate has issued, the amendment must be signed into law by the President "forthwith".
[7] 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.
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.
In Maguire v. Ardagh (2002), the Supreme Court held that Oireachtas Inquiries did not have the power to compel witnesses to attend and to make findings against them.
[27] The Thirtieth Amendment of the Constitution Bill 2011 proposed to allow Oireachtas Inquiries to make findings of fact and to balance the rights of the individual against the public interest; this referendum was defeated by 53% to 47%.
In O'Donovan v. the Attorney-General (1961), the Supreme Court held that the Electoral Amendment Act 1959 was unconstitutional and suggested that the ratio of representation to population across constituencies should differ by no more than 5%.
In Crotty v. An Taoiseach (1987), the Supreme Court held that the further transfer of powers from the state to the European institutions within the SEA was not "necessitated by the obligations of membership of the Communities" as provided for by the Third Amendment.
Referendums were also held to the allow the State to be bound by the Good Friday Agreement in 1998, and to ratify the International Criminal Court in 2001 and the Stability Treaty in 2012.
In McGee v. The Attorney General (1974), the Supreme Court found that provisions of Articles 40 and 41 guaranteed a right to marital privacy, and that contraception on prescription could not be prohibited to a married couple.
In Griswold v. Connecticut (1965), the United States Supreme Court came to a similar result, before finding for a general right to abortion in the first trimester in Roe v. Wade (1973).
The Eighth Amendment in 1983 gave constitutional protection to the life of the unborn, and therefore prohibiting abortion.
In March 1992, the Supreme Court ruled in Attorney General v X, commonly known as the X Case, that a teenage girl was entitled to an abortion as there was a risk to her life from suicide.
This addressed the injunction which the High Court had granted in the X Case to order the return of the girl to the country.
The Fourteenth Amendment was passed on the same day in 1992, to guarantee that the ban on abortion would not limit freedom to obtain or make available information relating to services lawfully available in another state.
This was in response to two cases: Attorney General (Society for the Protection of Unborn Children (Ireland) Ltd.) v Open Door Counselling Ltd. and Dublin Wellwoman Centre Ltd. (1988), which granted an injunction restraining two counseling agencies from assisting women to travel abroad to obtain abortions or informing them of the methods of communications with such clinics, and Society for the Protection of Unborn Children (Ireland) Ltd. v Grogan (1989), which placed an injunction restraining three students' unions from distributing information in relation to abortion available outside the state.
The Oireachtas chose to extend that period, meaning that for the duration of its existence, the Free State constitution could be amended at will by parliament.