President Michael D Higgins has signed into law the Government's Protection of Life During Pregnancy Bill.
Áras an Uachtaráin confirmed the move in a short statement this afternoon.
Mr Higgins received the Bill last Wednesday and was not required to make his decision known until midnight tomorrow.
He convened a meeting of the Council of State at the Áras yesterday to seek its advice on the Bill, which he could have opted to send to the Supreme Court to test its constitutionality.
The meeting was attended by 21 members of the 24-strong council and lasted for some 3½ hours.
It commenced at about 3.15pm following a brief photocall in the main drawing room of the President’s residence in the Phoenix Park and concluded at about 6.45pm.
Only three of the council were absent: they were former president Mary Robinson, and former taoisigh Albert Reynolds and John Bruton.
The 21 persons who attended, including seven members of the judiciary, still made it the biggest council since the Constitution came into effect in 1937.
The details of discussions at the council meetings are kept confidential.
President Higgins chaired the meeting, and those familiar with the process expected key contributions from Attorney General Máire Whelan and, possibly, from President of the High Court Nicholas Kearns. Mr Justice Kearns arrived to the Áras with a box containing documents.
Tánaiste Eamon Gilmore described the passing of the Bill as a milestone and a historic moment, particularly for the women of Ireland. “The core purpose of this legislation is about saving women’s lives,” he said. “It is about providing for a very basic human right. “It has been a long time coming.”
The Pro-Life Campaign would “devote its energies” to the “repeal of this unjust law” and would give “careful consideration in the coming weeks” on the best way to bring this about, Caroline Simons of the anti-abortion group said in a statement.
The Bill’s passage into law was a “very sad day”beause for the first time “it is now legal to deliverately target the life of an innocent human being”, she said. The Act “marks a new beginning not an end for pro-life activism,” she added.
Labour Senator Ivana Bacik was “delighted” the Bill had been signed into law and that Ireland “finally” had abortion legislation over 21 years after the X case, she said on Twitter.
Independent TD Mattie McGrath said Mr Higgins’ decision to sign the Bill into law was in some respects “ deeply regrettable” but also paved the way for legal challenges to commence.
“I remain committed to highlighting at every available opportunity the transparently unconstitutional nature of this Act which anyone not blinded by ideology or political expediency should clearly be able to see,” he said.