There were calls for a rerun of the children’s referendum after the court said the Government acted wrongfully by spending €1.1m on a campaign which was partially not fair, equal, or impartial.
Chief Justice Susan Denham said the Government placed the rights of the yes side above those against the vote, and this breached rules on the spending of funds in referenda.
The Government last night said it would study the full judgment from the five-member court.
Campaigners for the case argued that there had been a “constitutional crisis” and that the Government at the very least needed to pay back funds wrongly used in its information campaign.
Mark McCrystal, who took the case, said returning of the funds to the exchequer needed to be considered.
Independent TD Mattie McGrath, who opposed the vote last month, said a serious debate in the Dáil was needed.
Former MEP Kathy Sinnot, who had campaigned against the referendum, claimed the result of the vote had been “contaminated” and that the no side had been “disadvantaged” by the bias of the Government’s campaign.
She called on the Government to pay back the money and said a rerun of the vote was needed.
The Government said it was “carefully studying” the ruling but was restricted in commenting due to a further case against the referendum result, due to be heard in January.
“The Government welcomes the fact that Supreme Court has, for the first time since the judgment in 1995, provided some guidelines on the application of this important principle,” it said in a statement.
“The Government is committed to working within the parameters of the judgment delivered today in the conduct of future referendums, and will carefully study the conclusions of the court.”
Fianna Fáil said the court ruling was a “severe indictment of an increasingly arrogant Cabinet”.