Junior Finance Minister Simon Harris said the Government is "confident" Irish Water will pass European market tests.
His comments come after the European Commission expressed serious doubts over the utility's funding model.
In a report to be published today, the EC stated that Ireland faces a significant fiscal risk if Irish Water's borrowing cannot be taken off the Government books.
It has also raised concerns about "imbalances" in the economy - with unemployment, the banking sector and the high level of debt all requiring "decisive action".
Minister Harris says Ireland has "travelled" a long distance on the road to recovery.
"The Government has taken very decisive action in relation to Irish Water," he says.
"It has heard the concerns of a number of people and brought in a number of measures to provide clarity, including a Water Conservation Grant, which will be administered to all households who register for Irish Water.
"We're very confident that Irish Water will pass the Eurostat test, which is obviously an independent test, independent of the European Commission and indeed the Irish Government.
"We're very confident in that regard."
Yesterday, Irish Water said that landlords to