Social Protection Minister Joan Burton has challenged Irish Water to show that it has not spent excessively on consultants.
Minister Burton says the country does not need a "gold-plated" operation in the new utility.
The chairman and chief executive of Irish Water are to face questions at an Oireachtas committee tomorrow after it emerged that €50m has been spent on consultancy.
Minister Burton says that the taxpayer needs to hear that Irish Water is going to run a cost-effective operation.
"I think we want to see all costs under strict management, so that there's the best value for money for taxpayers," she said.
"And what we want are effectively run operations, as opposed to, if you like, gold-plated operations.
"So I look forward to hearing the views and the information that will be given at the committee meeting tomorrow."
Sinn Féin leader Gerry Adams called on the Government to make Irish Water compliant with the Freedom of Information Act and to move speedily to ensure that all relevant information about the establishment of the company is accessible and available to the public.
"People across the State are angry at this huge outlay of public money," he said.
"Such public anger is understandable considering the level of experience regarding water supply that already exists in the 34 local councils.
"Rather than spend this enormous amount of money on private consultants, Irish Water should have given this work to local authority staff. This would have been an immediate saving to the taxpayer."