In the most dramatic move in the life of this Government, Tanaiste Eamon Gilmore has put Taoiseach Enda Kenny on notice that the "reckless, macho and chaotic" behaviour of Environment Minister Phil Hogan, as described by senior Labour government insiders, is threatening the stability of the Coalition.
This is in reference to Mr Hogan's landing of Labour Ministers Pat Rabbitte and Jan O'Sullivan with the problem of defending the controversial property tax for ghost estates last Thursday.
But Mr Gilmore is himself under increased pressure following the intervention last night of party chairman Colm Keaveney on what he claimed were a range of Labour failures in Government, in particular the property tax and upward-only rents.
"The next tough decision demanded of Labour TDs seems likely to be the passing of an Act to enable the seizure of family homes by the banks," Mr Keaveney said in his call to arms to Labour grassroot members and backbench TDs.
Ahead of next Wednesday's by-election in Meath East, there is an increased feeling that if the Labour candidate, Eoin Holmes, does not finish in the top three, then Mr Gilmore's position as leader is likely to come into question.
Reflecting widespread anger within Labour, Mr Keaveney attacked the party's failure to achieve its main policy aims, particularly the failure to "secure the removal of upward-only rent reviews". He also criticised leader, Mr Gilmore, for standing over a "worsening" of issues the party had promised to protect and improve.
In a lengthy statement, Mr Keaveney accused the party of "running away" from the core principles the party was founded to protect – economic and labour rights.
Mr Keaveney cited Mr Gilmore's description of equal marriage rights as the "civil rights issue of our generation".
But he said: "These are not the issues that are leaving many families and individuals worrying over how to pay their bills and to retain the ability to raise their children with dignity.
"Unfinished estates and the fairness and objectivity of the new property tax and the failure to adequately address both will become an issue that will haunt both government parties," he wrote.
Relations between Mr Gilmore and Mr Kenny have soured significantly in recent days over the perceived "arrogant treatment" of Labour ministers by their Fine Gael colleagues.
The Labour leadership is furious at Mr Kenny for "indulging" the "reckless, macho and chaotic" behaviour of Environment Minister Phil Hogan, who they accused of "dumping" the ghost estates exemption controversy on ministers Pat Rabbitte and Jan O'Sullivan to defend, while he "skulked" off to Brussels.
"Hogan knew well it was controversial. It reflects the chaotic way he has mishandled many other aspects of his brief. He is surrounded by chaos," one senior Labour leadership figure said.
There is also renewed anger within Labour ministerial ranks over the ongoing mishandling of the health service by Dr James Reilly, described by one senior Labour source as a "car crash a week". News that tensions between the coalition parties are at unprecedented levels comes amid growing questions over the performance of Tanaiste Eamon Gilmore as leader of the party.
There is mounting doubt that Mr Gilmore is the right man to lead the party, particularly after last weekend's Sunday Independent/Millward Brown opinion poll, which had the party at just nine per cent, down from the 19 per cent it achieved in the February 2011 General Election.
The fears among Labour TDs reflect the 39 per cent of Labour voters who no longer have confidence in Mr Gilmore to lead the party.
"The venom is being directed at Gilmore and the leadership, which has brought us to the same level of support that Democratic Left finished with," said one senior party figure.
"This is f***ing amateur hour," said another. "Every guard and nurse is spitting fire at us and our man is going on about gay marriage and Savita."
Two Labour junior ministers have said the time has come for the Programme for Government to be renegotiated in order to re-establish the Labour agenda, and if that can't be done, their place in Government must be questioned.
"We are having rings run around us by Fine Gael, we are being too nice. We need to be far more assertive, and that needs to come from the top," said one.
It has also emerged that tensions between Mr Kenny and Social Protection Minister Joan Burton have increased significantly after it was claimed the Taoiseach would be micro-managing her department along with Dr Reilly's Department of Health, the two most problematic departments.
Senior Labour figures slammed Mr Kenny's "none- too-subtle attempt to hide the failure of Dr Reilly by dragging in the popular Ms Burton to cover up his defects".
Yesterday, Mr Kenny, speaking on the canvass in Meath East, distanced himself from the report that he will micro-manage Ms Burton and Dr Reilly, saying he is "too busy".
"What I am saying is that reporting is not always accurate," he said. When pressed on the matter, Mr Kenny said he has no intention of getting involved in the micro-management of every department "because I don't have time".
"I have a duty as Taoiseach to work with ministers that they live up to their responsibilities, not just the two departments you mention," he said.
On the property tax exemptions, Mr Kenny defended the sharp reduction in homes exempted from having to pay the property tax from over 43,000 to just over 5,000. He said: "The accuracy and the determination of who is liable now is far more updated than what appeared last year."
While the by-election has been seen as a two-horse race between the Fine Gael candidate Helen McEntee and Fianna Fail's Thomas Byrne, the scramble for transfers has intensified in recent days amid the controversy over the property tax exemptions for ghost estates.
This weekend, Sinn Fein called on all those supporting their candidate not to continue their support to any of the candidates from Fine Gael, Labour or Fianna Fail.