Fianna Fáil is joining other parties on the 'Future of Water Services' committee to seek the abolition of all domestic charges - including for excessive use.
But Fine Gael says there is no budget set aside for this and without excessive-use charges Ireland would be subjected to lengthy court battles and massive EU fines.
Anti-water charge campaigners say they are on the brink of an historic victory.
But AAA TD Mick Barry says the battle is not won yet, saying: "We are in the last 10 minutes of the cup final now.
"Our team, the Anti-Water Charges team, holds the lead but we're not in the slightest bit complacent on this and we will fight like men and women possessed over the month of March to ensure that when the final whistle goes, we will be the winners."
Earlier: Anti-water charge campaigners say they are on the verge of an historic victory.
The 'Future of Water Charges' committee is on the brink of agreeing to scrap all charges, and will not impose one for so-called excessive use.
People who paid their bills are also likely to get a refund.
Anti-Austerity Alliance/People Before Profit TD, Paul Murphy, says he thinks people who paid should be offered a number of refund options.
Mr Murphy said: "[The refunds] would include a tax rebate, which - if they were in receipt of a payment like a social welfare payment or pension - they [could] get added on or they could always go for a cheque in the post. Then we need to explore some of those."
People Before Profit TD Richard Boyd Barrett says it is an example of people power.
He said: "We are tantalisingly close to an absolutely historic victory for people power, for the boycott campaign, for protest.
"Fianna Fáil, Fine Gael and all those who championed water charges have now run out of excuses to continue to try and inflict these charges, because of a movement of people power."