Fianna Fáil backbencher Ned O'Keeffe quit the parliamentary party tonight ahead of a confidence vote in Minister for Health Mary Harney which she won comfortably.
Ceann Comhairle John O'Donoghue announced the outcome of the vote just after 9pm following a second evening of debate.
A no confidence motion was put down by the Labour Party but the Government's counter motion supporting Ms Harney won 83-73.
Despite resigning the party whip, Mr O'Keeffe abstained from voting for the Government but supported the blocking of the Labour motion because the counter motion did not express confidence in Ms Harney.
The Cork East TD had his request to speak during the debate turned down by Fianna Fail Chief Whip Tom Kitt. But he circulated a lengthy statement to reporters earlier, in which he condemned the health system.
He described the Government's health policy as one driven "privatisation and Americanisation".
Independent TDs, Finian McGrath, Jackie Healy-Rae, and Beverley Flynn also voted with the Government.
The vote was preceded by an often heated Dáil debate this evening. The Taoiseach Mr Ahern accused the Opposition parties of "playing political games" with the women who had been misdiagnosed.
"Of course the public, the women involved and their families have a right to be informed as soon as the information becomes available on a matter of this gravity but I have not been impressed at the rush to judgment to apportion blame and call for heads, knowing full well the extent of the careful analysis which was being undertaken to establish precisely what happened and why," Mr Ahern said.
The full truth and consequences of the misdiagnoses of nine women at Midlands Regional Hospital would be known once the HSE report into the affair was complete, he added.
"Once the experts complete their work then "effective accountability can be applied at all levels of the healthcare system.
"That is why the Minister for Health and Children has my support and the support of the entire Government", Mr Ahern said.
The Tánaiste Brian Cowen said despite the sound bites by any objective measure real progress was being made in the health services by a Minister who was trying to implement change.
However, Labour party leader Eamon Gilmore said Mary Harney's failure was so abject, her breach of trust so serious, "that she cannot continue in her post".
He said after all the promises that the HSE would bring about real improvements for patients, "we have been left with one of the worst scandals in the long litany of health scandals over which this Government has presided."
"So dysfunctional is the administration of the health service that both the Minister and the Chief Executive of the HSE are claiming that they knew nothing about the review of ultrasounds, even though the review of ultrasounds was reported in the newspapers in early September," Mr Gilmore said.
Mr Gilmore said the Minister's defence was she didn't know, she wasn't told and therefore was not responsible.
He also threw down a challenge to the Government TDs. "If you vote confidence in this failed Minister, then you are taking on yourself responsibility for her failures."
The days of Fianna Fáil TDs, going around their constituencies, muttering out of the side of their mouths about Mary Harney are now over."