A Fianna Fáil grassroots revolt has been sparked by Taoiseach Micheál Martin's decision to "snub" his deputy leader Dara Calleary.
Fianna Fáil councillors held an emergency meeting over Mr Calleary's appointment as Chief Whip rather than a full Cabinet position and agreed to raise concerns directly with Mr Martin.
Mayo county councillors from Fianna Fáil and Fine Gael also voted to write to the new Taoiseach to complain about the lack of ministerial representation from the west.
It comes after Mr Calleary revealed his anger over the appointment and the "incredibly difficult conversation" he had with Mr Martin after he realised he was the last Fianna Fáil TD to be offered a role.
"There weren't any other jobs on the table offered to me. We had a very difficult conversation and I told him I was disappointed," he told MidWest Radio.
"I hear the anger, I understand the anger, I was that angry person yesterday," he said in reference to the criticism of Mr Martin.
Meanwhile, the newly appointed Mayo County Council chairperson Richard Finn said there was a "lot of disquiet" over the new Cabinet. Councillors voted to instruct the chief executive to write to the Taoiseach outlining their concerns.
"The general gist of the letter would be to express our dissatisfaction with the way the ministries were distributed and where different jobs and portfolios went," the Independent councillor said.
The motion was agreed by Fianna Fáil and Fine Gael members of the council yesterday afternoon.
Separately, the Fianna Fáil councillors group in Mayo agreed to write to Mr Martin to express anger over the failure to appoint Mr Calleary as a full Cabinet minister.
Swinford councillor Michael Smyth told the Irish Independent: "We're all devastated that he didn't receive a senior role, but I think it's fair to say that Dara has to be the minister for the west. He has a big responsibility on his shoulders.
"We have to get on with it. There is anger at Micheál about this. I am absolutely angry at him."
Mr Smyth said the Fianna Fáil councillors wanted to "put on record our disappointment".
He added: "The decision not to make Dara senior minister is a deficit. We hope that balance will be corrected when we have junior ministers appointed next week. We're not happy about it."
John Maxwell, the chair of the local Fianna Fáil branch in Mr Calleary's Mayo constituency, told MidWest Radio he intended to resign from the party over Mr Calleary's exclusion.
However, he added that he had not made a final decision on this.
Mr Maxwell was sharply critical of the new Taoiseach, saying Mr Calleary had "Micheál Martin's back" when Fine Gael ministers were "wiping the floor with him".
Roscommon-based Fianna Fáil Senator Eugene Murphy said: "It's really concerning that Dara Calleary was not given a full Cabinet position."
Mr Calleary's predecessor as government chief whip, Fine Gael Senator Sean Kyne, defended the Fianna Fáil deputy leader's appointment, insisting "the voice of the chief whip was as strong as any other voice" at the Cabinet table.
The former Galway West TD told the Seanad: "I expect all members of the cabinet to work strongly for all parts of Ireland including the west of Ireland."
Several Fianna Fáil TDs have privately spoken of their outrage over Mr Martin's decision to exclude Mr Calleary from his line-up of full Cabinet ministers.
However, the Taoiseach defended his decision to appoint his deputy leader as Government Chief Whip.
After the first meeting of the new Cabinet, Mr Martin said he was faced with "very difficult" decisions when appointing his ministers and insisted the chief whip is a very important role in government.
The position comes with a salary of €40,000 less than a full Cabinet ministry.
Mr Martin said he was "not interested in the pay" his minsters receive but rather their "suitability" for the roles.
"Just in terms of Cabinet appointments, generally it is very difficult and I think there are quite a number of people who will be very, very disappointed that they didn't make the Cabinet."
"I know a number of parties who are upset by that but we have a limited choice. Each party leader has a limited number to appoint but calls have to be made in terms of the portfolios in particular and the desire to get ministers working immediately, particularly in housing and health," he added.
Meanwhile, Tánaiste Leo Varadkar poured cold water on speculation that former cabinet minister Michael Ring would be appointed to a junior role.
Asked about calls from Mayo county councillors to appoint Mr Ring, the Fine Gael leader said: "Any minister whose main focus is their own constituency is actually neglecting most of the country, so ministers must have a national remit and that's the way I would certainly expect all ministers to think.
"And the truth is there are 40 constituencies, there are 26 counties in the State. It's not possible for every constituency or county to have a minister every time, let alone two.
"There are counties, believe it or not, and there are constituencies that haven't had a minister for nine or 10 years and all those things have to be borne in mind when a party leader tries to appoint ministers," he added.