The Taoiseach has acknowledged that the compensation scheme established by the State four years ago for people abused as children in day schools is "not working".
Leo Varadkar was responding to Fianna Fáil leader Micheál Martin this afternoon after RTÉ reported that nothing has been paid to survivors under the scheme.
Five years ago, after a 15-year legal battle with the Government, Cork woman Louise O'Keeffe persuaded the European Court of Human Rights that the State was vicariously liable for the sexual abuse she suffered at the hands of her former national school principal, Leo Hickey.
The Government established an "ex gratia" - or out-of-court - compensation scheme for anyone falling into the same category as Ms O'Keeffe and who had stopped suing the State.
But applicants have sharply criticised it, and last July the Dáil voted that they should no longer have to prove that their abuser had already been reported to the authorities for similar crimes before he abused them.
The Department of Education has confirmed that the scheme has paid out no compensation despite receiving 50 applications over a four-year period.
This afternoon Mr Martin said "victims have been shamefully, cynically and cruelly treated by Government over the last number of years."
"The ultimate cruelty is to announce a redress scheme knowing in effect that the victims will never pass, the test of a prior complaint. That is the cruelest thing to do to any victim of sexual abuse, someone who has gone through the trauma of that abuse. And in essence that is what has happened."
He said it is "an appalling insult" to suggest that the only way a survivor can be included in the scheme is if somebody was abused before them and reported it to the authorities.
In November 2017 the Government appointed an Independent Assessor, the retired High Court judge Iarfhlaith O'Neill, to adjudicate on appeals applicants could make against rejections.
In early 2018, the judge told the Government that he was going to investigate whether or not the Department of Education was correctly implementing the European Court judgement. He said he would not be able to consider appeals until he reached a determination on that wider issue.
Last August, a Department of Education spokesman said the judge was expected to report within two weeks. But more than eight months later, Mr Justice O'Neill has yet to report. He has received submissions from the Department and interested parties and according to the Department is due to report "shortly".
Yesterday Minister for Education Joe McHugh told RTÉ News that he would have "no difficulty" in accepting whatever recommendations the judge might make.
In the Dáil, Micheál Martin asked when Judge O'Neill will report, and the Taoiseach said that he did not have a date for it but he has requested one.
Mr Varadkar said "there is no worse crime than a crime against a child. And I don't think there is any worse form of crime, or a crime that is more unspeakable than child abuse."
He said Judge O'Neill is examining about 20 cases and whether the interpretation of the O'Keeffe judgment is too narrow. He said a separate judicial review could hold up his work.
He added: "I do appreciate what you are saying. I think a scheme in which all applicants are rejected is a scheme that is not working. We need to review that and Judge Iarfhlaith O'Neill is reviewing the issues for us."
"But fundamentally what's behind this is was it the case that the State in some way could have acted and could not," he said.
This afternoon Minister McHugh told the Dáil that as of today 50 applications had been submitted to the scheme, 45 have been declined and the remaining five cases have yet to be determined.
He also said 20 applicants had sought an independent assessment.
Mr McHugh said he was aware that survivors of day school abuse cases are pursuing cases through the civil courts and are receiving settlements.
He was responding to Sinn Féin TD Maurice Quinlivan, who called on the minister to meet former students of Creagh Lane School in Limerick.
Mr McHugh said he took the issue very seriously, and repeated the Taoiseach's earlier comments that there was "something wrong here".
Additional reporting: Emma O'Kelly
If you have been affected by the issues raised in this story, you can call the Rape Crisis Centre national 24-hour helpline at 1800 77 8888