Micheal Martin believes a Brexit deal can be reached before October 31.
Yesterday Taoiseach Leo Varadkar handed Britain a Brexit lifeline and set the scene for a last-ditch deal after a three-hour meeting with Boris Johnson in Liverpool.
Mr Varadkar claimed significant progress towards a deal has been made, with the Taoiseach saying he was “absolutely convinced” there now exists “a pathway towards an agreement in the coming weeks".
And Fianna Fail leader Micheal Martin has agreed that a deal can be reached before the October 31 deadline.
He told Morning Ireland on RTE Radio One: "I think it is conceivable. I think it will be very challenging, but it certainly is conceivable.
"And we are again coming to a cliff-edge so to speak, and I think in that context everyone on all sides will want to avoid a no deal and we want to try and reach an accommodation.
"That is why I think it's important we get into a negotiating channel where you don't have ongoing public commentary on this proposal or that proposal. We've had too much of that in the past two to three weeks.
"The other good news I thought coming out of yesterday's meeting was the focus on future British-Irish relationships post-Brexit.
"I've been saying this for two and a half years, new structures in my view would have to emerge, something like the Nordic council in a post-Brexit situation to maintain ongoing engagement between the Irish and British Governments."
Martin also rejected suggestions that a referendum on the issue in Northern Ireland was the best way forward.
He added: "I'm not so sure a referendum is the way to resolve this, it's possible but that can lead to its own difficulties.
"There may be no need for a referendum if everybody worked towards the resolution of this because I don't think anyone wants a no deal.
"I don't think the Unionist community want a no deal, I don't think the people of Northern Ireland want a no deal, we in the Republic don't want a no deal and Britain doesn't want a no deal."
