The Taoiseach yesterday postponed for 24 hours a decision on whether to refer the report on vaccine trials involving children in institutional care to the Laffoy Commission on Child Abuse, following Labour objections.
The postponement followed Labour claims that such a referral might not be allowed under the present terms of reference of the Laffoy Commission.
Mr Ahern said yesterday this issue had been checked, but that he would take legal advice again on the matter before returning to the Dail this morning.
The Laffoy Commission was established to look at physical and sexual abuse of children in institutions. Labour's health spokeswoman, Ms Liz McManus, said yesterday this might not allow for the investigation of the vaccine trials.
The Department of Health report concerns three trials carried out in the 1960s and 1970s, and raises questions over whether appropriate consent was given on behalf of the children in care who were used in the trials.
When the Taoiseach sought to have the Dail agree to the referral yesterday, the Labour leader, Mr Ruairi Quinn, suggested the Dail pass a motion explicitly empowering the Laffoy Commission to investigate the report. This, he said, would ensure no legal challenge could be mounted on the basis that this was outside the terms of reference.
Mr Ahern agreed he would "consider whether Deputy Quinn's amendment is necessary overnight and I would be prepared to move it on tomorrow's Order of Business, should it be deemed so. We have obtained legal advice on this matter but we will check it again".
He said he would not be opposed to holding a short debate on the matter.
However, he again rejected Fine Gael demands to allow the Oireachtas Committee on Health and Children to investigate the issue.