A leading oncologist has said that the new National Children's Hospital should be built at St James's Hospital in Dublin, and not at the Mater.
Dr John Kennedy, who is also Chair of the St James's Hospital Medical Board, said his hospital has the right facilities for children, it has public transport access, and has the backing of Crumlin Children's Hospital.
Yesterday, the Mater Hospital Group submitted a revised plan for the new hospital after the original one was refused planning permission.
But Dr Kennedy said the Mater is not the right site.
"We feel that the combination of access, clinical excellence - which is very important - and space will make this a winning bid," he said.
"Most importantly, we feel that our bid has the unequivocal support of the Crumlin hospital as the preferred bid.
"Crumlin is the largest provider of tertiary paediatric services to children in Ireland."
However, Master and CEO of the Rotunda Maternity Hospital in Dublin, Sam Coulter Smith, has insisted that the Mater is the correct location for children.
He says St James's is not the answer, but the debate should not be about existing hospitals.
"This shouldn't be an argument about Crumlin and Temple St.," he said.
"This is about provide absolute gold-standard quality care for the children of Ireland."