The Oireachtas committee set up to propose a future for the funding of water services should curtail its witness list in order to meet an April 1 deadline, a Fine Gael member has said.
Dublin South West TD Colm Brophy, who is one of the Government's representatives on the committee, has warned that any attempt to hold a series of public hearings with witnesses could derail the timeline.
He was speaking after suggestions from some members that the Right2Water group could be asked to give evidence.
An expert commission, chaired by Kevin Duffy, has already held a public consultation with a range of interest groups, political parties and individuals.
"There are a number of key things that we have to take on board. The report set out the questions that need to be answered and that's where we need to focus," Mr Brophy said.
"There is a tight, complex deadline for coming up with a solution."
Mr Duffy's report said that the "vast majority" of people should no longer have to pay water charges.
The Oireachtas Committee, chaired by Independent Senator Pádraig Ó Céidigh, has been tasked with coming up with proposals that can be put before the Dáil in the coming months.
"I'm of the clear view myself that we should keep the number of witnesses very tight. Witnesses should have something to contribute that can inform our decisions. There should be no stretching this out," Mr Brophy said. "On April 1 we kick back into water charges. The committee has to have carried out its deliberations or we revert to the default position."
The committee meets at least once a week and has already heard from a number of Irish Water representatives and Mr Duffy.
Last week, it discussed public ownership of the water system with officials from the Department of Housing, Planning, Community and Local Government, and a senior counsel.
Next Wednesday, members of the Public Water Forum will give their views on transparency at Irish Water.
Both Fine Gael and Fianna Fáil are closely monitoring the committee's work as the abolition of water charges formed a key part of the negotiations that led to the formation of the Government last May.
The Dáil vote which will follow on from the committee's report will be hugely contentious.