Independent TDs Catherine Murphy, Stephen Donnelly and Róisín Shortall are about to set up a new political party.
The three TDs are linking up with Senators Katherine Zappone and Jillian van Turnhout, who are both the Taoiseach’s nominees in the Seanad.
Mr Donnelly confirmed talks about the setting up of the new party are under way.
"There are talks going on and at this point, I am not in a position to say who, what and when," he said.
The new centre-left party is likely to be set up by the end of the month.
The three TDs and two Senators are understood to have been holding a series of meetings in Leinster House about the establishment of the party.
The party will lean heavily on centre-left economic policy, social justice campaigning and political reform.
The quintet believed to be planning to add additional candidates to their list once they are established.
"They've been meeting quite a lot about forming a political party and are due to announce soon, probably by the end of the month. This has been going on for a while," a TD told Independent.ie.
The group are believed to have approached another Oireachtas member to join them, but were turned down.
Speculation is now intensifying within political circles about the formation of the party.
So far this year, Lucinda Creighton has set up her Renua party, which contested the Carlow-Kilkenny by-election and Shane Ross is still working on forming a new Independents group.