The 'future of water services' committee is seeking fresh legal advice after a number of changes to its draft report.
Fine Gael has accused Fianna Fáil of "siding" with Sinn Féin to see the word "excessive" removed from the report, along with other changes.
It now looks increasingly likely that Fine Gael and Labour will not vote in favour of the final report.
The committee has now gone through three of the four chapters of the report and Fine Gael has repeatedly lost votes.
The word "excessive" usage was replaced with "wasteful/abusive" while "levies" has been replaced with "penalties".
However, Fine Gael insists this means what is being recommended no longer adheres to the EU water services directive.
The chair of the committee Padraig O'Ceidigh has sought fresh legal advice and may advise the committee this evening that the report no longer adheres to the EU directive.
A Fine Gael spokesperson says Fianna Fáil sided with Sinn Féin to make the changes to undermine an agreement on a compliant report.
A vote on the final report could take place tonight, but Fine Gael and Labour say they would not be in a position to back it - they would be outnumbered by others.