Fine Gael is demanding that an expert in EU law provides advice to the Oireachtas Water Committee on the issue of charges.
The prospect of a general election being prompted by the scandal moved a step closer last night as a war of words erupted between Fine Gael and Fianna Fail.
Committee chairman Padraig O Ceidigh has told colleagues he is prepared to allow a "majority report" to be produced if no deal is agreed.
A decision by Housing Minister Simon Coveney to voice his concerns in a letter to Mr O Ceidigh was dubbed an "interference" by Fianna Fail TD Barry Cowen.
He was supported by Solidarity TD and committee member Paul Murphy, who described Mr Coveney's intervention as "unprecedented".
In the letter, sent on Thursday night, Mr Coveney said the proposed regime will place Ireland "at odds" with the EU.
However, Mr Coveney yesterday defended the move, saying the Government would not introduce flawed legislation aimed at resolving the stalemate just to avoid an election.
Householders who waste water or use excessive amounts should have to pay a bill, and there was no "moral or legal argument" to justify using taxation to fund "wasteful" use, Mr Coveney said. Speaking to the Herald, Mr Coveney added that people were "sick of the argument" and wanted a resolution to the issue.
"In my view, and in the view of Fine Gael, people who are wasting water and using excessive amounts of water should have to pay for that," he said.
"I do not see any moral or legal argument that could suggest that general taxation should be funding the excessive or wasteful use of water in households.
"We have no intention of taking those people to court; we're simply sending them a bill," he added.
"But let me be very clear, I'm not going to produce an outcome to this process which is politically expedient to avoid elections."
His comments came as the Dail committee was adjourned until next Tuesday, pending legal advice as to whether a draft deal will allow Ireland to conform with obligations under the Water Framework Directive, which imposes a "polluter pays" principle.
Meanwhile, Taoiseach Enda Kenny has brushed off suggestions that the row over water will lead to a snap election.
"I expect we will arrive at a conclusion next week that will be in keeping with the requirements of the law, at the same time understanding water is a commodity not to be wasted," he said.