A site value levy is being considered in the government formation talks, which could heap more of a tax burden on city dwellers.
It would mark a major overhaul in the way homeowners' property tax bills, which have been unchanged since 2013, are calculated, and could hit those who live close to transport links and amenities.
The Green Party has proposed the site value tax in the talks with Fine Gael and Fianna Fáil in recent days.
The proposal would place a levy on the value of land as opposed to the market value of a property.
An immediate overhaul of the local property tax (LPT) is not likely, but a commitment to examining the site value tax idea, as part of a review of the LPT, could be included in the programme for government.
Fine Gael has expressed a willingness to examine the proposal, with one source saying there is "no principled opposition to it".
But Fianna Fáil has been resistant, with a source insisting the existing LPT is "here to stay" as it raises around €480m per year.
At present, the property tax is calculated on the market value of a home, whereas the site value tax would effectively be a charge on where that home is located, with land close to amenities and transport links typically worth more.
LPT valuations have not changed since 2013 - with successive governments postponing the revaluation process for fear of a backlash from homeowners because rising property prices would lead to larger tax bills.
The Greens proposed a site value tax in their manifesto, arguing it would discourage land speculation and urban sprawl, while ensuring that housing is developed on land close to existing amenities and transport links.
Fine Gael labelled the idea "a garden tax" during the election, claiming homeowners with gardens and rural landowners would be disproportionately affected, but has since softened its view.
Economist Ronan Lyons is a strong proponent of the site value tax, arguing it could be structured to avoid it hitting rural landowners, farmers or those who own large plots of land but have little income.
He said his research indicated that the burden of a site value tax would fall on richer households.
"It punishes people who waste valuable land," he said.
"The value of the site is created by society, not by an individual, its jobs nearby, transport nearby or amenities nearby."
The interdepartmental group which devised the property tax in 2012 said the site value tax would face difficulties as people more easily understand tax based on property values.
Property tax bills are currently calculated on what the market value of the property was in May 2013.
A review to take into account house price increases was due last November, but was postponed by a year. There are now doubts as to whether this new deadline will be met as legislation is needed to give Revenue, which collects the LPT, powers to put new arrangements in place.
Meanwhile, Fine Gael, Fianna Fáil and the Green Party leaders met with Independent TDs Marian Harkin, Michael McNamara and Michael Fitzmaurice yesterday to update them on the progress of the government talks.
The Independent TDs were told they would not have the same level of input into the programme for government as those who were involved in the 2016 negotiations.
Constituency deals similar to those Fianna Fáil struck with Independents Jackie Healy-Rae and Mildred Fox in the late 1990s were more likely than ministries, the meeting was told.
Afterwards, Mr McNamara said: "Their clear priority is agreeing a programme for government that is acceptable to their memberships, that is understandable. I think Independents will feature but in a relatively low-key way. Ministries were not discussed."
The tripartite talks are continuing amid expectation that a deal on a draft programme for government will be reached next week.