The construction of the new National Children's Hospital is expected to get the green light by Cabinet tomorrow.
It follows an official examination of the projected €1 billion cost of the facility, set to make it the most expensive children's hospital in the world.
The approval from the government will mean that building can start at the site of St. James, despite concerns about the location from some opposition groups, particularly by the Connolly for Kids group.
The main hospital will be 7 storeys high with the majority of the building at 4 storeys.
It will feature 380 single inpatient rooms, 42 beds in a critical care unit and 18 neonatal units.
The aim is to bring together Temple St., Our Lady's Hospital Crumlin and the National Chidren's Hospital Tallaght, and have it completed by 2021.
The price gone has gone from an original estimated of €400 million to €1 billion due to construction inflation.
More than €120 million has already been spent on development plans first at the Mater site and now St James, without a brick being laid.