The Jack and Jill Foundation says it has grave concerns over the location of the new National Children's Hospital.
The charity - which cares for some of the country's sickest children - says the site of St James' Hospital in Dublin city centre is entirely inappropriate.
After over 20 years of work on the project, its latest incarnation is facing increased objections, with some saying it should be built on the campus of Connolly Hospital in Blanchardstown.
Jack and Jill CEO Jonathan Irwin will speak at a conference of the National Association of GPs this afternoon.
He is urging doctors to speak out against the planned location:
The €650m development would combine the services at the three existing hospitals in Crumlin, Tallaght and Temple Street.
