THE Government has admitted that up to one in five homeowners will face flat-rate water charges as it won't be possible to install a meter on their property.
As mixed messages over the introduction of charges continued, Transport Minister Leo Varadkar apologised for the confusion.
But Labour Party criticism of Environment Minister Phil Hogan grew, with an MEP calling for him to be moved out of the position.
The Department of the Environment estimated at the weekend that around 300,000 homes -- roughly one in five -- initially won't be suitable for having water meters installed, but this figure would reduce with time.
Mr Varadkar said one in five mainly older houses and apartments won't be metered and these homeowners will pay a fixed-rate charge based on the number of people living in the house and the property size.
"There will be about 20pc of houses and apartments that won't be able to be metered in the normal way.
"What they do in other countries is that they estimate the charges based on the size of the house and the number of people in it. But that is something that will have to be worked out at a later stage," he said.
Mr Varadkar said he acknowledged there had been confusion over the issue.
"I apologise for that. I know the people are struggling with bills at the moment and that the cost of living is increasing, and certainly nobody in the Government wants to scare people about charges that, let's face it, are not going to come into play for over two years," he said on RTE's 'The Week In Politics'.
The controversy over the introduction of the household and water charges is straining relations within the Coalition.
A Labour Party MEP last night called for Phil Hogan to be moved to another job as sniping between the coalition partners continued.
Leinster MEP Nessa Childers said she had advised Tanaiste Eamon Gilmore to take the environment post when the Coalition was formed.
Ms Childers, who has clashed a number of times with party leaders, said Mr Hogan should be reshuffled out of the job.
"I am absolutely convinced we wouldn't be in this situation if Eamon Gilmore had been Environment Minister.
"I don't feel at all confident with this minister (Mr Hogan) now. I think he should be reshuffled because it is too serious now," she said.
Several Labour TDs criticised Mr Hogan over the weekend.