Sinn Féin is appealing for members of the Oireachtas to support their petition calling on the President not to sign the controversial Water Services Bill.
The Bill was passed by the Seanad last evening by a margin of 28 votes to 25.
The legislation contains measures to bring in the reduced water charges announced by the Government last month.
The Bill now goes to President Michael D Higgins for his signature, and Sinn Féin Senator David Cullinane said they're looking at other options.
Mr Cullinane said: "We're awaiting legal advice, we've given a commitment to people to use every instrument at our disposal to defeat this charge and this Bill.
"We will still seek to petition the President.
"We are in direct contact with the office of the President seeking clarification on the implications of the issue itself, so obviously this is something that the party is considering."