Enda Kenny and Micheal Martin have reached out to Independents and smaller parties as they scramble to secure support ahead of next week's Dail vote on who should be the next Taoiseach.
Mr Kenny met members of the Independent Alliance in Leinster House, seeking support for a Fine Gael-led government.
Fianna Fail leader Mr Martin has spoken with a number of independents as well as smaller parties including the Social Democrats.
Neither Mr Kenny nor Mr Martin is likely to secure the majority needed to secure the office of Taoiseach and form a government in a Dail vote on Thursday.
Both are striving to get the most votes in a bid to strengthen their bargaining positions ahead of further negotiations.
One Fine Gael source said next Thursday's vote will be a "piece of theatre" and that "things will start to get serious in terms of actually trying to put a government together" after that.
"At this stage we don't need Independents to back us on Thursday, we just need them not to back him (Mr Martin)," another source said.
Fianna Fail sources said talks with Independents and others remain on an "informal basis".
"The Independents are not going to do a deal before Thursday. They are going to enjoy all of this," a source said.
The six-strong Independent Alliance was represented by Dublin TDs Shane Ross and Finian McGrath, as well as deputies John Halligan and Sean Canney, at a 90-minute meeting with Mr Kenny yesterday morning.
Mr Halligan said they presented the Taoiseach with their Charter for Change, which includes proposals on Dail reform and improvements to services in rural Ireland.
"Mr Kenny said he would look at it. He would seriously consider it. He said he is trying to form a government with independents," Mr Halligan said.
"He said he will come back to us with his response to the charter and also his plan for Dail reform in the next week and we'll meet again.
"It was a good meeting. I believe other parties want to meet us, so we'll see what happens."
Katherine Zappone said she met Mr Kenny and has also had talks with Mr Martin but did not say if she would support either candidate for Taoiseach, saying that would be "premature".
Independents Noel Grealish and Mattie McGrath both confirmed they have been contacted by Fianna Fail and Fine Gael.
Jobs Minister Richard Bruton said last night that Fine Gael will meet again next week to "reflect on the dis- cussions that have been had".
"Some of their ideas are very interesting. I think you could build those into a programme for government," he told RTE.
Mr Bruton ruled out talking with Sinn Fein or AAA/PBP and said his party is not currently in talks with Fianna Fail as they are putting forward their own nominee for Taoiseach.