Fianna Fail has established a three per cent lead over Fine Gael, according to the latest opinion poll.
The Sunday Independent/Millward Brown poll was conducted at the height of the Anglo Tapes controversy, when Enda Kenny claimed that an "axis of collusion" existed between Fianna Fail and Anglo Irish Bank.
In the previous Millward Brown poll, both parties were level on 26pc, but today's results indicate that Fianna Fail is poised to win more than 50 seats in any future general election.
In contrast, as Mr Kenny struggles to control the escalating political fallout from the departure of five "conscience-led" TDs, the Fine Gael-Labour Coalition – which won a record 113 seats in the 2011 election – is staring into the abyss of a possible Brian Cowen-style meltdown.
Today's poll, in which FG (26pc) and Labour (8pc) have the support of just over one-third of the electorate, indicates that the Coalition's voter support has declined by an unprecedented 21pc before the Government has reached the mid-term mark.
Such has been the fall in support for the government parties that the anarchic combination of SF (19pc and independents (18pc is three per cent more popular than the Coalition.
Fine Gael, should its slide continue, is poised to lose more than 30 seats; Labour, which elected a record 37 TDs, is on current figures facing a struggle for existence as a major political party.
Such a scenario is likely to be of major concern to ambitious possible future leaders such as Sean Sherlock and Alan Kelly.
The party, at eight per cent (party leader Eamon Gilmore's satisfaction rating of 16pc is in a similar league to that of Brian Cowen), is now tipping at the edges of its worst electoral performance since 1987 when, with 6.7pc of the vote, 12 male TDs were elected.
Commenting on the figures, Paul Moran of Millward Brown warned that the most worrying feature of the result for Mr Gilmore was the breaking of the psychological barrier where "exactly half of his own supporters are discontented with his performance".
It is believed within Leinster House that Mr Kenny's aggressive stance on the Anglo Tapes and Fine Gael's "provocative" positioning on tax cuts were fuelled by private polling research by the party that revealed a major swing of middle-class votes back to Fianna Fail.
The revelation in today's poll that the strategy has back-fired is not the only bad news for the Coalition – it also shows the Taoiseach's crusade to abolish the Seanad is in difficulty. Mr Kenny has invested a great deal of his own political capital in what is seen within a hostile Fine Gael and a largely indifferent Labour Party as a personal initiative.
Amid growing concerns over what has been described as Mr Kenny's "autocratic" style of government, support for the abolition of the Seanad has fallen by 10 per cent from the previous poll.
Since the first Millward Brown poll last February, when the abolition of the Seanad secured the support of 57pc, the fall in the Yes vote is a significant 14 per cent. The speed of the decline, when compared with the relatively unchanged nature of the No vote, suggests that support for the abolition of the the one state institution that can say no to the Government is crumbling.
Mr Moran, of Millward Brown, noted of the decline that "it seems the opening skirmishes in this debate have been lost by Mr Kenny" and that "those in favour of reform have been more sure-footed in their argument that ending the Seanad will lead to a lack of accountability".
A defeat of the Seanad referendum, given its close association with Mr Kenny, would cause serious damage to the Taoiseach's authority.
The possibility of such a defeat is high, given the stark levels of dissatisfaction with this administration – Mr Kenny has a dissatisfaction rating of 64pc, while the Government's dissatisfaction rating is 75pc.
Significantly, the three cabinet members with the highest levels of dissatisfaction with their performance are the Fine Gael troika of James Reilly (25pc), Enda Kenny (17pc and the previously well-regarded Michael Noonan at 8pc.
Discontent with the Coalition is also evident. Only 11pc of voters are supportive of a current Fine Gael-Labour option – the same level secured by the alternative of a Fianna Fail-Sinn Fein alliance.
These figures also indicate that voters are increasingly open to supporting a new party.