The Mater, Rotunda and Temple Street hospitals are working together to rescue the National Children's Hospital planned for the Mater site in Dublin.
The original plan was rejected in February by An Bord Pleanála as the proposed 16 floor building was deemed to be too high with a negative impact on the Dublin skyline.
But the Sisters of Mercy order has agreed to offer the old Mater adult hospital site for inclusion in new plans which could create a tri-located hospital with adult, maternity and paediatric services on one site.
Dr Sam Coulter-Smith has said that the three hospitals have been working together for some time to provide an efficient and better service, and they are keen that the Mater site would be the located site as there are ''desperate capacity issues''.
Speaking on RTÉ's Morning Ireland, he said that these new plans would answer issues in relation to the height and density of the hospital as it was originally designed before the plans were rejected.
Dr Coulter-Smith said this put forward the Mater again as the pre-eminent site for this development.
He said the three sites - the Mater, the Rotunda and Temple Street - were virtually co-located anyway with a lot of cross institutional appointments and it would be a matter of cementing these links and bringing the hospitals closer together.
He said there were currently serious capacity issues at the Rotunda maternity hospital where close to 10,000 women were due to deliver this year.
He said there was a desperate need for a bigger and better service and that the new plans afforded the hospital the best opportunity to link in with the new development.
Dr Roisin Healy of the National Children's Hospital Alliance has said that the plans should be examined along with other sites and there should be a proper scoring system set up to assess them.
Senator John Crown has said that the fresh proposals appeared to overcome the objections which prompted An Board Pleanála to reject the original proposal.
The Review Group into the National Paediatric Hospital, which is headed by Dr Frank Dolphin, has been ordered to make a recommendation on the best site within 56 days.