The St Vincent's Healthcare Group has insisted it must own the land on which the proposed new National Maternity Hospital will be built in order to protect patients.
Chairman James Menton has told the Oireachtas Health Committee that having dual ownership on the Elm Park site would present significant risks to patient care.
He said the group's aim is to improve healthcare for women using a partnership approach.
Committee members are examining concerns around the proposed move of the National Maternity Hospital to Elm Park.
The new hospital would be a subsidiary of SVHG, which also runs the public and private St Vincent's hospitals on the same site.
Sinn Féin's David Cullinane said the ownership structure for the new hospital was "convoluted".
People Before Profit's Bríd Smith said anything less than full ownership had the appearance of not being in the control of the people.
The group also said there were no religious conditions attached to the transfer of the shares from the Religious Sisters of Charity.
Fine Gael Senator Martin Conway asked why fewer than five terminations were carried out at St Vincent's hospital between 2016 and 2021.
He also said it was important to put on the record that sterilisations were not carried out at St Vincent's as an exclusive procedure.
Consultant oncologist Janice Walshe said terminations were carried out at the hospital, but she said more complex cases were transferred to Holles Street because they have more resources and proper psychological care.
She added that she has never had direct or indirect influence from a religious order.
The Government is expected to sign off on the move at tomorrow's Cabinet meeting following a two-week pause on a decision to allow for time to examine the details of the move.
The three coalition leaders will discuss the proposal this evening.
The Department of Health has also dismissed a suggestion that work is underway to draft a codicil to the agreement to clarify the term "clinically appropriate".
SVHG also says the Religious Sisters of Charity transferred their shares without any conditions requiring the practice of any Catholic ethics or religious ethos.
The co-leader of the Social Democrats urged the Government not to sign off on the National Maternity Hospital tomorrow.
Róisín Shortall says more time is needed to address a number of outstanding aspects including the lack of a definition for the term "clinical appropriateness."
Speaking on RTÉ'S Drivetime she said SVHG said it would have no problem with a legal definition being outlined in the document.
Deputy Shortall said this cannot be done by tomorrow.
She said she also asked Chairman James Menton if a serious approach was made to him about selling the site.
She said he replied that there was an approach made five years ago which was dismissed and since the new group has been in place there has been no serious approach by the State.
She said she is "very disappointed, but not entirely surprised" that the Government seems to want to ramp this through tomorrow.
'Overwhelming' support for NMH move - Board chair
The Chairperson of the Medical Board of the SVHG has expressed "overwhelming" support for the relocation of the National Maternity Hospital to the Elm Park site.
In a letter to Minister for Health Stephen Donnelly, seen by RTÉ News, Dr John Hollan wrote that "despite allegations to the contrary, the simple fact is that the St. Vincent's Group is now a secular organisation."
Dr Hollan warned that further delays would "serve only to deny women access" to medical care.
"Many of our consultant staff already work across the two sites, and we see this as a necessary and natural evolution in the modernisation and enhancement of obstetric and neonatal care in Ireland. It is long overdue," Dr Hollan said.
The Medical Board represents more than 250 clinicians working across the St Vincent's Hospital Healthcare Group.
Minister Donnelly said he would correspond with the health committee in order to address concerns raised about the term "clinically appropriate" in the constitution of the National Maternity Hospital.
The constitution states the hospital will be able to carry out healthcare procedures which are legal and "clinically appropriate".
However, politicians and medics opposed to the St Vincent's move believe it is open to interpretation and might prevent women from receiving procedures, such as termination of pregnancy or sterilisation.
It is one of the issues which will no doubt be raised with representatives of the SVHG at the committee hearing.
It is also likely the group will face questions as to why the land is not being gifted to the State.
NMH project bogged down
A former master of the Coombe Maternity Hospital in Dublin says the new NHH project has gotten bogged down in complex technicalities and legalese, but the basic issues of trust and transparency remain.
Speaking on RTÉ's Morning Ireland, Dr Chris Fitzpatrick said he believes clinicians want to do what is right in the new hospital but he is not confident that they will have the independence they require, despite all the assurances.
He said it was unbelievable to think the Cabinet is poised to invest €1bn of taxpayer money without seeing the correspondence between the nuns and the Vatican regarding the transfer of the Religious Sisters of Charity's shareholding in St Vincent's Healthcare Group to St Vincent's Holding CLG.
"If there's no problem in relation to these documents, then they should be disclosed. If there is a problem, we should actually see them," he said.
The recently retired obstetrician, who resigned from his role on the relocation project board of the National Maternity Hospital back in 2017, said that disclosing the documents is the best way to allay concerns people have about the hospital project.
Additional reporting: Mícheál Lehane and Paul Cunningham