Serious complex A&E care - amongst other things - could be removed from the Royal Glamorgan Hospital in Llantristant, under plans unveiled today.
For the past 18 months, five health boards and the Welsh Ambulance Service have been working on plans which would transform hospital services in South Wales and Powys under the banner 'The South Wales Programme'.
Under four options being considered, the programme suggests the best 'fit' would be to have specialist centres based at the University Hospital Wales in Cardiff, Morriston Hospital in Swansea, a new critical care centre in Cwmbran, Prince Charles Hospital in Merthyr Tydfil and the Princess of Wales Hospital in Bridgend.
Programme leaders say the Royal Glamorgan Hospital will retain an accident and emergency unit if the plans are approved, but that the level of care provided would be on the same level as a nurse-led minor injuries unit.
Other services affected include complex in-patient children's services and consultant-led maternity and neonatal care.
Clinicians acknowledge that although some services could be removed from the Royal Glamorgan, others could be transferred there from other hospitals in South Wales.
Dr Graham Shortland, Executive Medical Director for Cardiff & Vale UHB
Doctors say the proposals are about providing the best care to patients all the time, as the current system isn't sustainable.
Already some are calling this a 'downgrade' of the Royal Glamorgan Hospital, although clinicians leading the programme say that is not the case.
But they acknowledged it could be a 'hard sell' to those who feel angry, and say they must work on informing the public.
Grant Robinson, Medical Director of Aneurin Bevan Health Board
I recognise that people will be angry and people will demand answers to why we're doing this. And it's up to us, through the consultation process, to provide that information.