In a statement, he said he initially contested the election “in a spirit of lifelong public service and a love of country”.
“I believe deeply in this country, its dreams, its hopes and above all its people,” he said.
“The office of Uachtarán na hÉireann (Irish president) is the highest in the land and the pinnacle of public service. It is an office that must be untainted by controversy or distraction.”
The 54-year-old Dubliner added he knew the campaign would be “robust and challenging”, however issues that have surfaced in recent days “have given me cause to reflect”.
“I made a mistake that was not in keeping with my character and the standards I set myself. I am now taking steps to address the matter,” the statement added.
“I have also thought long and hard about the potential impact of the ongoing campaign on the wellbeing of my family and friends.
“Taking all these considerations on board, I have decided to withdraw from the presidential election contest with immediate effect and return to the arms of my family.”
