The plan for Dublin's directly elected mayor is in danger of collapsing due to the objections of one of the four councils in the capital.
Councillors in Dublin have to decide by the end of the month whether a referendum on the introduction new position will take place on the same day as the local elections.
But all four councils have to agree to the vote for it to take place on May 23. The referendum is intended to give Dubliners a say on whether the post will be created.
But Fingal County Council is threatening to veto the plan by objecting to the referendum being held in the first place.
Councillors are concerned about Fingal's income stream and are also objecting the structure of the new post, arguing there are no efficiencies contained in the plans.
Dublin City Council, South Dublin County Council and Dun Laoghaire-Rathdown County Council are in favour of the referendum taking place.
The votes on holding the referendum will be held at the end of the month and must be passed by all four councils, according to the Department of the Environment.
"If the vote is to go ahead, it has to be all four and it has to be the majority of all four. It would be divisive otherwise. There is no proposal to go back and change it. You have to have unanimity from all four councils for it to go ahead," a spokesman said.
But the Mayor of Fingal, Fine Gael's Kieran Dennison, said councillors are against the proposals for the directly elected mayor as currently set out.
"The overwhelming view is the proposed structure is half-baked. There are absolutely no efficiencies in this," he said.