Around 800,000 bills issued by Irish Water since April have passed their pay-by date, but the utility has refused to disclose how many bills have been paid, according to Socialist Party TD Paul Murphy.
Speaking in the Dáil, Mr Murphy said he had submitted a Freedom of Information request to find out how many people have paid their water bill.
He said the information he was given was that by 18 May some 800,000 bills had passed their pay by date, but Irish Water had refused to say how many bills have been paid.
Mr Murphy said he had submitted the FOI because he asked Taoiseach Enda Kenny four weeks ago in the Dáil how many people had paid and was told to "toddle along" to a meeting with Irish Water in Leinster House that day where his questions would be answered.
He said Irish Water confirmed at that stage that more than 600,000 bills had passed their pay-by date, but he said the utility refused "outright" to say how many bills had not been paid.
Mr Murphy said Irish Water told him that giving these figures would not be "helpful".
Minister for Jobs, Enterprise and Innovation Richard Bruton told Mr Murphy he could complain to the FOI Commissioner if he was unhappy with the response he received.
Mr Murphy responded by saying the Taoiseach had said Dáil questions should be answered fully and the minister had not answered his question as to how many people had paid their water bills.
He asked had the Government discussed the levels of payment with Irish Water and has there been communication between the utility and the Government?
He also asked was the reason the payment figures were not being disclosed was because payment levels "are on the floor"?
Minister Bruton said Mr Murphy would have to table a question with the relevant minister.
He said Ireland needs a modern water system for a modern economy and a utility is in place to achieve this.
Irish Water has said that it is not in a position to give any details about how many households have not yet paid their water bills.
It said it began its first billing cycle in early April and it will continue until mid-June.
The company said that as this is the first time that domestic water bills are being issued to all users of the public water and wastewater systems in Ireland they are working with customers to ensure they have all of the correct information.
It said his process will take time and for these reasons it is not in a position to confirm payment information at this time.