The chairperson of the Policing Authority has said she has "a degree of confidence" but is concerned about the ability of the Garda Commissioner to carry out her role while the Charleton Tribunal is under way.

The inquiry will investigate an alleged smear campaign by senior gardaí against garda whistleblower Sergeant Maurice McCabe.

Garda Commissioner Nóirín O'Sullivan yesterday assured a public session of the Policing Authority that the work of gardaí is not being affected by the ongoing controversies.

Policing Authority Chairperson Josephine Feehily this morning said she has confidence in Commissioner O'Sullivan's capacity with her senior team to run the organisation but it is the parallel running of her job and servicing the tribunal which raises a question.

Speaking on RTÉ's Today with Sean O'Rourke, Ms Feehily said the work of the Charleton Tribunal is hugely important but should move at a pace to bring a finality to a "saga" that is "potentially corrosive" to policing and to garda morale.

She said the issues before the Charleton Tribunal now need to be investigated as they have been damaging to public confidence in the gardaí and the morale of members. It will give all parties a chance to say their piece, she said.

RTÉ’s @BrianDowling4 on the significance of the Policing Authority chairperson's comments on the Garda Commissioner and Charleton inquiry pic.twitter.com/zvFWSk8qhE — RTÉ News (@rtenews) February 24, 2017

The concern about the culture of An Garda Síochána has been there for some time, she said, and the Policing Authority has pressed the organisation to do a culture audit, which is now out for tender.

The issue of "how to create an environment for speaking out" needs to be properly implemented, she said.

She added that the authority is concerned that the focus of senior garda management will be on the tribunal rather than on policing but said the commissioner is looking at how best to manage it.

Ms Feehily said she is also concerned the motivation, energy and morale of the gardaí will be affected negatively by the tribunal.

Minister for Children and Youth Affairs Katherine Zappone has said that she had not heard the interview but was aware of what was said by Ms Feehily on the Today with Sean O'Rourke programme.

She said the independent Policing Authority is a huge advance in the reform of the gardaí and she needed to listen carefully to what Ms Feehily said.

Labour leader Brendan Howlin has meanwhile said Ms Feehily can play an active role if she wants the Garda Commissioner to stand aside.

Speaking on RTÉ's News at One, Mr Howlin said she can make a recommendation to Government to ask the commissioner to stand aside but "from what Josephine Feehily has said they haven't reached that decision and that is fair".

He questioned how the commissioner will be able to focus on everything and said she should stand aside and let someone else drive garda reform while the tribunal is ongoing.