The Office of the President has confirmed it has received a letter from Sinn Féin, the Technical Group and a number of Independents asking Michael D Higgins not to sign the Water Services Bill into law.
Citing the "degree of widespread public opposition" - the letter states that the matter is of such national importance that a referendum should be held.
The Office of the President has responded, saying that President Higgins has received the Bill and is considering the constitutionality of its provisions.
Sinn Féin's Aengus O'Snodaigh is calling on Michael D. Higgins to refer the bill to the Council of State.
"We believe that the introduction of a new tax on people and in particular a tax on water is such an important issue that we believe the President should refer it to the Council of State, and we would hope that Council of State would then refer it to the Supreme Court to test if it is constitutional," he said.