The Public Accounts Committee will ask the head of the Department of Public Expenditure as well as one of its top officials to answer questions about the spiralling costs for the national children's hospital.
PAC chairman Sean Fleming said the committee would frame questions for department secretary general Robert Watt in a general way about spending so he would be required to appear before TDs.
Mr Watt has already declined to appear before the Oireachtas Health Committee on the scandal.
PAC also want the department's chief procurement officer, Paul Quinn, to appear and answer questions on the same matter.
Mr Fleming said it was “totally unsatisfactory” that the committee had already written to Mr Quinn on the same issue, but he had failed to point out that he was on a board overseeing the hospital.
PAC would express "grave disappointment” that that information was not relayed by Mr Quinn to the committee.
The committee is also seeking legal advice on the new revised PwC terms for a review into the €1.4bn hospital spend and whether it would identify people or whether it would just be government, as TD Catherine Murphy said, who knew the people involved when the report is completed.
The committee is also to consider a request by Prof Chris Fitzpatrick, the former Master of the Coombe maternity hospital, to appear over the hospital debacle and outline his concerns.
