Keith Davies: Labour's Llanelli AM ill in hospital
The Llanelli Assembly Member Keith Davies is seriously ill in hospital, BBC Wales understands.
Mr Davies, 71, was admitted to the University Hospital of Wales in Cardiff on Wednesday night.
A Welsh assembly Labour Party spokesman said the AM was undergoing tests at the neurosurgical unit.
Mr Davies was first elected to the assembly in May last year at the age of 70, taking back Llanelli for the Labour Party from Plaid Cymru by 80 votes.
The Welsh Labour spokesman said: "On Wednesday night, Llanelli AM Keith Davies was admitted to University Hospital of Wales in Cardiff. He is currently undergoing tests at the neurosurgical unit.
"Everyone in Welsh Labour wishes him a speedy recovery."
Several get-well messages have appeared on Twitter.
Liberal Democrat AM Eluned Parrott wrote: "Prayers and best wishes to Keith Davies - get well soon."
Conservative AM Angela Burns described Mr Davies' ill health as sad and referred to him as "a nice guy", while Plaid Cymru AM Bethan Jenkins said her thoughts were with Mr Davies and his family.
Mr Davies qualified as a teacher before becoming a school inspector and subsequently became director of education for Mid Glamorgan and Carmarthenshire.
On his website, the father-of-two describes himself as a lifelong socialist "with a strong sense of community".