Update 4pm: Fine Gael is asking the Oireachtas committee on water to get legal advice on three concerns over its final report.
The party believes the recommendations might bring Ireland into conflict with European law.
It wants a senior barrister, who specialises in EU affairs, to rule on whether the report would require the State to establish someone's motive for using excessive water before fining them.
The party also wants advice on whether it would be legal to have a flat-rate penalty for excessive water users.
The concerns are the same ones raised by Simon Coveney in a letter to the committee's chairman last night.
Update 12.29pm: Former Labour Party leader Joan Burton says the row over water charges makes the Government look 'helpless and hapless'.
Fine Gael can't agree with Fianna Fáil if we should take the advice of the Oireachtas water funding committee.
Micheál Martin agrees that we should scrap bills, but Housing Minister Simon Coveney has warned that it could lead to EU fines.
Former Tánaiste and Labour Party leader Joan Burton says the argument over water is embarrassing.
"I think it makes the Government look hopeless and hapless to be honest," she said.
"Just reading some of the committee stuff, there are two very significant Fianna Fáil members on that committee - Willie O'Dea and Barry Cowen - and essentially I think what they've done is pushed Fine Gael into a very, very difficult corner."
Simon Coveney has written to the committee discussing the future of water charges, saying their final report might leave us open to major fines.
The Minister’s letter comes after the committee delayed its final vote, to get another set of legal advice.
The committee voted yesterday to get a new legal opinion on its final report, which would scrap charges, refund existing bills, not require meters in new homes, and which makes only passing mention of penalties or levies for wilfully wasteful use.
Last night Simon Coveney wrote to the committee saying the current wording poses problems, and could leave Ireland facing millions in fines from the EU.
He says if only ‘wilful’ wasters are punished, the State would have to prove the motives of the household.
Minister Coveney also says a possible penalty for using excess water is not good enough, because if it is a flat-rate penalty, there is no incentive for high users to cut back.
He aslso said that not having mandatory meters in new homes means it will be difficult to identify wasteful users to begin with, and that puts us on a collision course with Europe.
The Minister says he is not trying to interfere, but rather put concerns on the record.