Keith Davies was rushed to accident and emergency late on Wednesday night. The Labour AM, 71, had attended a function organised by a public affairs group earlier in the evening.
Mr Davies is a father of two, who is married to wife Heddyr.
Keith Davies, the Labour Assembly Member for Llanelli, is seriously ill at the University Hospital of Wales in Cardiff.
Mr Davies, who's 71, was elected to the assembly after a career as a teacher and subsequently as Director of Education at Carmarthenshire County Council.
Here's the full statement from a Welsh Labour spokesman:
Labour's Chief Whip in the Assembly, Janice Gregory AM, has officially reprimanded Keith Davies following the censure motion against him this afternoon. I'm told it's one of the most serious sanctions open to her.
Llanelli AM, Keith Davies, has told Assembly Members that he is sorry for his actions following his censure.
He was criticised after he admitted getting drunk on a night out in Cardiff and then returning to his hotel with a woman he had met so that they could drink some more.
AMs have passed on a motion of censure on the Llanelli AM Keith Davies for his drunken behaviour at a Cardiff hotel. Mr Davies spoke briefly. He apologised to his fellow Assembly members, his constituents, Assembly staff and in particular to his family.
Llanelli AM Keith Davies faces his vote of censure later as Nick Powell reports here but I gather he's already faced one difficult meeting. A Labour source tells me that Mr Davies made 'an extremely humble apology' to fellow Labour AMs at a meeting yesterday (Tuesday)