A Fine Gael TD has broken ranks and voted against the Government in a Dail motion over controversial cutbacks at Roscommon Hospital.
Denis Naughten and his Roscommon-South Leitrim constituency colleague Frank Feighan faced intense public pressure to oppose the downgrading of services.
Mr Feighan backed the coalition plans but Mr Naughten sided with protesters demonstrating outside the Dail angry at the shutdown of the hospital's A&E department.
The Government comfortably won the motion by 50 votes, but Mr Naughten could now face expulsion from the parliamentary party over his dissent.
Earlier Taoiseach Enda Kenny signalled further turmoil lies ahead over the future of smaller hospitals.
Defending Roscommon's A&E shutdown, Mr Kenny said the decision was not easy but was made on the back of serious fears about patient safety from a health watchdog and consultants.
He pointed out a Health Information and Quality Authority (HIQA) study which also highlighted recommended reforms at 10 hospitals. They include Roscommon, Navan, Louth, Portlaoise, St Columcille's hospital in Loughlinstown, south Dublin, Ennis, Nenagh, St John's hospital in Limerick as well as Mallow and Bantry hospitals in Cork.
He said it was a fact of life that conditions in a number of smaller hospitals were not satisfactory and Health Minister James Reilly was committed to reform of the health system.
Protesters travelled from Roscommon to demonstrate outside the Dail after Sinn Fein tabled a motion opposing the downgrading of services. Mr Feighan was heckled by demonstrators as he tried to address them.
Mr Kenny insisted serious concerns about patient safety because of a lack of medical staff, as outlined in the HIQA report, was the sole reason for the changes at Roscommon. But Fianna Fail leader Micheal Martin accused Mr Kenny of abandoning pre-election commitments to smaller hospitals around the country.