Four opposition parties have tabled a joint motion calling for an immediate end to water charges.

The motion - signed by 39 TDs - will be debated after a government is formed, but Catherine Murphy of the Social Democrats says the decisions on Irish Water should be taken immediately, in the Dáil, rather than in negotiations between Fianna Fáil and Fine Gael.

It places direct pressure on Fianna Fáil to refuse any Fine Gael deal that ignores their pre-election promises on the issue.

Sinn Féin, AAA-PBP, Social Democrats, the four-strong Independents for Change and unaligned Independents Catherine Connolly, Seamus Healy and Thomas Pringle confirmed the motion will be placed before the Dáil at the next available opportunity as the future of the utility continues to dominate government formation talks.

Speaking at a joint press briefing outside Leinster House, the parties said that, regardless of any minority Government deal, Fianna Fáil has an obligation to ensure water charges are scrapped by voting with them in the Dáil.

Were Fianna Fáil's 43 TDs to support the motion, the proposal would gain a Dáil majority of 82 TDs, and thus become law.

The move come as Fine Gael and Fianna Fáil hit a stumbling block of negotiations at Trinity College Dublin on the formation of a minority government.