The Public Accounts Committee has called on the Department of Finance to develop new systems to improve the "crude" estimates it uses to forecast tax revenues.
In a draft report covering issues raised in the 2001 annual report of the comptroller and auditor general, the committee also criticised several "significant" cases of a loss of value for money by public bodies and Government departments.
These included an extra cost of €13 million in a car-park project at Beaumont Hospital, even though the initiative was designed to provide extra income of €1.8 million for the hospital.
The draft highlighted delays in IT projects at the Irish Blood Transfusion Service that led to an increase in project costs to €9.3 million from €4.26 million.
It also criticised the Office of Public Works for buying buildings to house asylum-seekers and then failing to obtain the planning permission required to make them fit for their intended use.
The outgoing committee chairman, Mr John Perry, said successive reports from the comptroller served to highlight numerous flaws in the management of public expenditure. Such reports failed to prompt "major change" in the management of expenditure by accounting officers in public bodies.
The draft says the revenue estimates drawn up by the Department of Finance were based on information that may be several years out of date.
The final report for 2001, based on the committee's hearings in 2002 and 2003, will be sent within weeks to the Minister for Finance, Mr Cowen.
