Eamon Ryan has said he will try to win Green Party TDs around to support the EU’s Comprehensive Economic Trade Agreement (CETA) with Canada.
This comes as the party remains divided on whether or not to support it.
At its core, the dispute is over the environmental impact contained within the deal.
Neasa Hourigan says this issue was specifically vetoed by the Greens during negotiations, specifying that the argument centres around a proposed investment court system.
Deputy Hourigan is one of two Green Party TDs – along with Dublin South Central's Patrick Costello – who've said they won't back the Government on the full ratification of the trade deal.
Both members have raised concerns on the deal, saying it could allow multinationals to sue Ireland if strong climate and social rights protections are brought in.
Solidarity TD Mick Barry says he doesn't believe the Greens should support CETA.
He said: "For any serious environmentalist or any serious green activist, the investor court system would allow big corporations to sue for loss of earnings in cases where sound environmental policies were introduced which limited their ability to maximise profits."
CETA is the trade deal that was struck between the EU and Canada three years ago when Brexit negotiations began. A number of aspects of the agreement are already in place, but a Dáil vote is required to officially sign off.
The programme for government set out the coalition's policy priorities – something Deputy Hourigan said this CETA issue simply isn't a part of.
She said: "There was an attempt to put CETA in, and it was flagged by us - I think by me - that that shouldn't really be in there.
"We made plenty of compromises. Over the last few months I've had to vote for things I am deeply unhappy with and uncomfortable about... but we made a deal.
"We have tried to adhere to that deal. This isn't in the deal."
She noted that 11 other countries also haven't ratified the CETA deal, so there's "no time pressure" in getting it passed.
Reporting by Sean Defoe / Additional reporting Kate Demolder
Picture by: JULIEN BEHAL PHOTOGRAPHY / RollingNews.ie