A legal challenge to the attendance of so-called "super junior ministers" at meetings of the Cabinet could be heard in late May.
Sinn Féin TD Pa Daly claims the Constitution limits the number of Government ministers to 15 and binds them to confidentiality about their discussions.
Today, Attorney General Rossa Fanning said since the foundation of the State people have attended Government meetings without being a member of the Cabinet and said "people have done the former without having been in the latter".
Mr Fanning said it is necessary for more people than a Government of 15 to attend the Cabinet and said it is important he outlines how modern Government operates.
He said the Government Chief Whip has historically attended Cabinet meetings.
The Attorney General said it is not for Mr Daly to say the hearing of the case is urgent and added Mr Daly had first raised the issue in a letter five years ago and did not do anything about it
However, Mr Fanning said: "I do agree that it's in the public interest given the nature of the case that it heard promptly."
Ms Justice Mary Rose Gearty said she would give time for the opposition to prepare its response and set a date for eight weeks to return to court.
She said: "The only problem is that is April Fools Day".
Mr Daly's Senior Counsel Feichín McDonagh said he was happy with that.
A date for a full hearing of the case is expected to be set on 1 April and the court was told it could be heard by the end of May.
The "super juniors" who have been appointed are Hildegarde Naughton of Fine Gael, as well as Seán Canney and Noel Grealish of the Regional Independent Group.
Fianna Fáil's Mary Butler has been appointed Government Chief Whip as well as a "super junior" minister with responsibility for mental health.
The first time the practice of appointing "super junior" ministers occurred was during the 1994 "Rainbow Coalition" of Fine Gael, Labour and Democratic Left, when Pat Rabbitte was permitted to attend Cabinet meetings.
