Director General of the Health Service Executive Tony O'Brien will step down from his position with effect from close of business tomorrow following the CervicalCheck cancer controversy.
In a statement released by the HSE this evening, Mr O'Brien said that he had made his decision "in order to avoid any further impact to the delivery of health and social care services, and in particular the cancer screening services that have become the focus of intense political debate in recent days".
He added that there were clear communication failures surrounding the CervicalCheck audits, but that he is confident a review announced by the Government last week "will demonstrate the quality and value of the CervicalCheck programme once it is complete".
Mr O'Brien said that he looks forward to engaging with the review and that he will co-operate fully with the preliminary inquiry headed by Dr Gabriel Scally.
Mr O'Brien said he has been proud to lead the health services and the many staff who have worked tirelessly and with great dedication to provide health and social care services in a very challenging environment.
His early departure has followed two weeks of controversy over cervical smears and the Vicky Phelan case, and a powerful interview on RTÉ radio this morning by Emma Mhic Mathuna who has terminal cancer.
It also follows revelations in three HSE memos today at the public accounts committee, which he had seen in 2016.
Tonight the Department of Health said no health ministers had seen those memos.
Minister for Health Simon Harris said Mr O'Brien informed him of his decision to step down in a meeting on this evening.
"I would like to express my thanks to Tony O'Brien for his many years of dedicated public service," he said.
"I know that he is standing down from his role today because he believes it is in the best interest of rebuilding public confidence in the wake of the issues which have arisen in CervicalCheck (Ireland's national screening programme).
"Tomorrow, the Cabinet meeting will again discuss this matter and the further measures which can be put in place to care for and support the women and families affected."
Sinn Féin leader Mary Lou McDonald has said the move "is a necessary first step in achieving accountability".
"It is regrettable that it ultimately took terminally ill women taking to the national airwaves to demand that Mr O'Brien be held to account in order to secure his resignation," she said in a statement.