A Fianna Fáil TD has said he's concerned a small party such as the Greens could 'walk out' of any Fianna Fáil / Fine Gael coalition government, and that he would have "much preferred" a national government.
John McGuinness also said he would like to see the pandemic unemployment payment continue until the end of the year.
It comes as government formation talks have been continuing between Fine Gael, Fianna Fáil and the Greens this weekend, with the aim of reaching a deal over the next week.
Deputy McGuinness, Fianna Fáil TD for Carlow-Killenny, told On The Record With Gavan Reilly that he believes government formation talks have now gone on for too long.
Deputy McGuinness said: "I think the parties are looking over their shoulder far too much, and I would like to see more speed in the delivery of a new government.
"What we don't want to do is end up with a government creating expectations that simply cannot be delivered on.
"A new government needs to be built on truth and reality."
He said he would have preferred to go into 'full government' with Fine Gael in 2016, suggesting the confidence and supply arrangement has "damaged deeply" the Fianna Fáil party.
He also argued that a new government will have to be formed that's "centre-left", as Fine Gael was "defeated" in January's election.
Deputy McGuinness said: "I think that it is now important that Fianna Fáil would drag [Fine Gael] in that direction, because [Fine Gael] have failed in their nine-and-a-half year in government.
"I would have much preferred a national government, where we would have significant numbers."
He said that the Greens will have to brought on board for whatever 'radical steps' are needed to change society and economy for the better, and that he's concerned they could 'walk out' of any government that is formed.
'Truthful and transparent plan'
According to Deputy McGuinness, the Fianna Fáil membership wants to see any new government protecting agriculture and making clear what a 7% reduction in emissions would mean to them.
He said: "If it's not a truthful and transparent plan for the next government, you'll find the grassroots of the organisation would reject it.
"Members of the parliamentary party have not been informed on a weekly basis of the up-to-date position regarding the talks, which is a failure in terms of informing people who are central to support for the next government.
"Fine Gael, in terms of some of the commentary coming from those meetings, seem to be determined to collapse the talks... that does not give confidence to all of us who are on the margins of this and want to see a government for five years."
Elsewhere, Deputy McGuinness said he believes the pandemic unemployment payment should last until the end of the year - a call that has previously been made by parties such as Sinn Féin.
He observed: "You need to keep the money being paid in the way it is being paid right now. But the quicker you get people back to work, the lesser number of people that will then be on that payment - it's a balance you need to strike.
"It was always only a temporary payment, but you can't just cut it off or taper it off quickly, because people are now relying on it.
"You will have to make arrangements to ensure that it's part and parcel of the payment until the end of this year... that enable people to move within the economy and get themselves back working.
"There is far too much uncertainty out there, and it's far better to plan for the longer period in paying that money than it would be to cut it off at a point when we're still ensure."
However, he suggested the payment will "naturally ease itself off" as more people return to work.