Simon Harris is facing calls to make a statement to the Dail about an investigation into former senator Martin Conway.
The former Fine Gael senator resigned from his parliamentary party after admitting to being arrested by gardai for being intoxicated in public.
In a statement issued by the Fine Gael party, Mr Conway said he had been arrested on Dublin’s main thoroughfare O’Connell Street on January 22 for being in an intoxicated state “due to consumption of sleeping tablets and alcohol”.
He said he had let himself down and resigned from the Fine Gael parliamentary party, adding that a disciplinary process would now commence.
It has also emerged that the senator is subject to a separate investigation over allegations of “inappropriate behaviour” to a female staff member.
Speaking in the Dail, Sinn Fein TD Louise O’Reilly called on the Ceann Comhairle Verona Murphy to set time aside to allow Mr Harris to make a statement on the matter.
“The leader of the Fine Gael party, Simon Harris, must come into the Dail to make a statement about his party’s investigation into Senator Martin Conway for inappropriate behaviour to a female staff member,” Ms O’Reilly said.
“We have written to the Ceann Comhairle to request that time be set aside for the Tanaiste to do just this.
“We know there was an investigation by Fine Gael, but what we do not know is what Simon Harris knew or when he knew it.
“We also know from media reports that a sum of 10,000 euro was made in payment.
“I am sure the Ceann Comhairle will agree with me that a sum of 10,000 euro suggests a very, very serious incident. We are entitled to know what happened.
“I am requesting that time will be set aside to facilitate that statement.”
Party colleague Pearse Doherty also called on Mr Harris to come before the House.
Ms O’Reilly added: “I am asking you that you would put time aside to facilitate the Tanaiste to make a statement to clear up the serious questions that are now in the public domain.
“I am asking that the Ceann Comhairle would use her office to put aside some time to facilitate the Tanaiste making an important statement.”
Ms Murphy said: “I do not have the authority to do that and you bring it to the Business Committee as per motion.”
Mr Conway, from Co Clare, was recently re-elected to Ireland’s senate, the Seanad.
The senator, who has a visual impairment, had been nominated by sight-loss agency Vision Ireland.
Following his resignation from the parliamentary party after reports of his arrest emerged, Mr Conway “apologise unreservedly”.
Mr Conway added: “I let myself down. I would also like to apologise to the members of An Garda Siochana for having to deal with this matter.
“I have resigned from the Fine Gael parliamentary party.”