The first opinion poll since the Budget shows a devastating ten point drop in support for Fianna Fáil.
The Red C poll in tomorrow's Sunday Business Post shows that for the first time since polling began, Fine Gael is seven points ahead of the main government party.
Red C carried out its monthly poll on Monday, Tuesday and Wednesday - at the height of the medical card controversy.
Fianna Fáil is down an unprecedented ten points in a month, to just 26%.
Fine Gael, meanwhile, gained five points to 33% - giving the party a seven point lead over Fianna Fáil.
Labour is up six to 15, the Greens drop one to 6%, Sinn Féin is up one to 10%, the PDs drop one to 2%, and Independents and Others are unchanged at 8%.
Just 23% of those polled said they were confident the Government can manage the public finances out of the current downturn, a fall of 19 points since last month, while 59% said they were not confident and 21% said they did not know.
Fine Gael welcomes 'positive poll'
Fine Gael has welcomed what it described as a very positive poll for the party.
A spokesperson said that while it was just one poll, it accurately reflected the anger amongst the public and hunger for a change.
He said the party remained focused on the aim of becoming the largest party in the next Dáil and to form the next Government.
A Labour Party spokesperson said that while everyone expected a fall in support for Fianna Fáil, nobody expected it to drop by this much.
He said Labour was pleased at its own performance, which it saw as reflecting a strong performance since the resumption of the Dáil.
The challenge now was to hold on to it.
Meanwhile, Fianna Fáil is sticking to its policy of not commenting on a poll, good or bad.
Independent TD Finian McGrath, who withdrew his support from the Government last week, said the poll sends a clear message to the Government to scrap the medical card proposal and reverse education and disability cuts.