A Dáil debate on the Judicial appointments Bill has been suspended amid confusion over the number lay people involved.
The new laws will see an independent commission set up to decide how judges are appointed.
But there is a dispute over whether the commission must have a majority of members from the legal profession.
Sinn Féin is backing the bill - its Justice spokesman Donnchadh O'Laoghaire says including members of the public will not make the commission any less professional.
"It's been sometimes put out there that these lay people would be inexpert - absolutely not," said Mr O'Laoghaire.
"There is serious criteria in there that they would have to reach an understanding of the law, the court, all the work and so on.
"This could include legal academics, this could include people from free legal advice clinics and so on."