The Sinn Féin leader has admitted to withholding the real reason behind the resignation of a Senator who sent inappropriate texts to a minor.
Niall Ó Donnghaile sent the messages in September 2023 prompting a complaint to the party and a reference to the PSNI, who found no offence occurred.
Mary Lou McDonald told the Dáil Sinn Féin knew Mr Ó Donnghaile would resign from the party after a meeting on October 5th 2023.
He eventually stepped down more than two months later - citing health reasons with Ms McDonald praising him in a statement.
Ms McDonald told the Dáil they did not release the real reason behind Mr Ó Donnghaile's resignation out of concern for his health.
"Following the complaint we were advised that Niall Ó Donnghaile was again suffering from a mental health crisis and was deemed medically unfit for work by his doctor," she said.
"We were very worried that publicly naming him would be dangerous to his health - and this is not to make an excuse for his behaviour".
'Questions deserve an answer'
Fine Gael TD Ciaran Cannon was one of a number of TDs with questions about why the Seanad was not informed.
"You were an active participant in an effort to protect the party, issuing a press statement to thank him for his service," he said.
"I have a few questions, like many others, that deserve an answer today: why did you not immediately seek Senator Ó Donnghaile's resignation in September at the same time as you were notifying the PSNI and social services of these text messages?
"Why didn't you inform the Seanad that your Seanad leader was in fact no longer a member of your party?"
The Dáil is hearing statements on child protection with Tánaiste Micheál Martin accusing Sinn Féin of playing by its own rules.
In a statement, Minister Martin said it appears the Oireachtas was "misled" on the full reasons for Senator Ó Donnghaile's resignation - and said the party’s "track record of concealment and secrecy is shocking".
Additional reporting: Jack Quann
