A deal on a programme for government could be reached on Sunday after negotiators from Fine Gael, Fianna Fail and the Green Party met until the early hours of the morning.
The leaders of the three parties are expected to meet again later to discuss outstanding issues.
Green Party TD Ossian Smyth, who is part of his party's negotiating team, tweeted at 4.30am on Sunday: "The three negotiating teams agreed most of a programme for government this morning. A small number of issues have been left to the party leaders to decide later today. A lot of good stuff in there!"
On Saturday, Green Party deputy leader Catherine Martin raised hopes of the process concluding this weekend.
"I think an agreement can be reached some time this weekend. It is hard to judge and I can't give an exact hour or a day but I think it will be this weekend," she told RTE News.
"There are a number of issues that need to be ironed out. I have to respect the confidentiality of the process so I'm not going to name those items but there a number of items that still need to be teased out."
The programme for government could run to more than 100 pages and the detail of that will be worked out by party leaders on Sunday.
It will then have to be put to the membership of each of the three parties for consideration.
Taoiseach Leo Varadkar said on Friday that he thinks a government could be in place by the end of June or early July if members accept the deal.
