Micheál Martin has insisted minority governments can work - if people are willing to try.
Delivering an oration at the 93rd General Liam Lynch Memorial Mass in Newcastle, Co Tipperary, the Fianna Fáil leader defended his party's refusal to enter a so-called "grand coalition" with long-term political foes Fine Gael.
— Fianna Fáil (@fiannafailparty) April 10, 2016
Deputy Martin said: "The insistence on a majority or nothing is a very Westminster-focused belief and completely out of step with countries similar to Ireland which have proportional representation and multi-party systems.
"Minority governments can work if people are willing to try - and they represent a much truer reflection of the need to change our politics than simply change titles.
"Three out of the four Scandinavian countries currently have minority governments.
"They are getting on with their business in stable, successful democracies."
There have been weeks of wrangling since February's general election threw up a massive schism in the electorate.
After exploratory talks on Saturday, both parties said they would discuss how a viable minority government could work when negotiators met again on Monday.
The ground-breaking proposal for a full partnership government would end more than 90 years of bitter civil-war era rivalry, and has overwhelming support from within Fine Gael ranks.
But Mr Martin said his party had campaigned to put Fine Gael out of power, adding that majority governments could be "arrogant, divisive and unfair".
Mr Martin also took a swipe at critics who have slammed the six weeks of political uncertainty.
"Finding a new way of reconstructing an old model of governing will simply represent carrying on and once again failing to deliver change.
"We are offering a major compromise. We are not refusing to change. We will agree to a process which can allow a government to be formed and for that government to have reasonable security based on a fully transparent framework.
"The greatest achievements of our country have come from responding to genuinely radical changes.
"The best way of responding to radical change in our politics is to be willing to change how we govern and not just shuffle the pack in a new way."
The Dáil is due to meet on Thursday, when the shape of the new government may be made more clear.