LABOUR Party Senator Jimmy Harte who suffered from a "tragic fall" in Dublin's city centre at the weekend had collapsed a number of times recently.
Mr Harte has a history of recent ill-health due to a heart condition, it is understood.
He had a stable night in hospital last night.
Mr Harte had been in a critical condition after undergoing treatment for a brain injury.
It is understood that he is still in an induced coma.
Gardai are investigating the incident after the Donegal politician was found collapsed with serious head injuries in the south inner city.
Mr Harte, 55, was said to have a fractured skull, massive clot and an underlying brain injury.
It is likely to be 48 hours before a full prognosis can be determined by doctors.
While initial indications pointed to an assault, gardai said the accident was most likely the result of a "tragic fall."
Mr Harte was found at 3am Friday morning in the Newmarket Square area of Dublin 8, just off Cork Street, where he owns an apartment, which he lives in while in Dublin.
"Our initial thought was he had collapsed because he has a heart complaint. There was severe damage. The gardai are trying to piece it together," a family member said.
Afterwards, they met with his brother, who was also at the match.
Mr Harte returned home in a taxi around midnight and went for a takeaway but never made it back to his apartment.
He was found collapsed on the street and was brought to the nearby St James's Hospital by ambulance.
He was later transferred to Beaumont Hospital to be admitted to the neurological treatment centre, which specialises in head traumas.
His wife, Mary, was called in the early hours of the morning to be informed of his condition.
Tanaiste Eamon Gilmore have been in contact with the Harte family throughout yesterday and was keeping up to date on his condition.
Mr Harte is married with four children. His daughter, Amy, works in the Labour Party press office. Last night, the family were by his side in Beaumont Hospital.
However, he took part in a recent charity football match on a team of Oireachtas members at the Aviva Stadium, which he organised.
Mr Harte is the son of former Fine Gael TD Paddy Harte.
The senator joined Labour three years ago and ran as a candidate in the Donegal North-East constituency.
He is a former member of Donegal County Council, elected in 1999, and served as Deputy Mayor of Letterkenny in 2010.
FIONNAN SHEAHAN, DANIEL MCCONNELL and JOHN DRENNAN