Former Justice Minister Nora Owen has said a partnership government could mean very little legislation gets passed in the new Dáil.
Her comments came after acting Taoiseach Enda Kenny indicated negotiators were working towards a foundation document for a partnership government.
Both Fine Gael and Fianna Fáil are due to resume talks with Independents tomorrow.
Nora Owen said: "Can you just imagine a partnership based on 'you're a Minister for two and a half years, you're a Minister for two and a half years', and half way through the government, all that you were working on as one Minister all gets put to one side and the new Minister comes in saying 'I'm not interested in that half-done piece of legislation' and puts in the bin.
"Nothing gets passed."
A new poll released by the Sunday Independent today has found 39% of people would rather see Micheál Martin as Taoiseach, in preference to Enda Kenny.
The Dáil is to vote on a new Taoiseach on Wednesday.
Meanwhile, a member of Fianna Fáil's negotiating team has rubbished claims the party is considering entering a partnership Government.
The idea was mooted by Enda Kenny at the end of last week and could see both Fine Gael and Fianna Fáil TDs holding ministerial offices over the course of a five-year term.
Fianna Fáil TD for Dublin Bay South Jim O'Callaghan said his party wanted a minority Government.
"We have been engaged in talks with the Independents for the past two weeks, trying to get their support for a Micheál Martin (and) Fianna Fáil-led minority government," he said.
"We're committed to try to form a Fianna Fáil minority government, which is the change the Irish people voted for."