Update 4.40pm: A former Justice Minister says the appointment of an outsider as Garda Commissioner is the first step in reforming the force.
Drew Harris is the first outsider to be appointed to the Garda top job and may bring some of his leadership team from the PSNI.
He has previously worked with Gardaí on cross-border policing matters.
At least two current senior members of Garda management were in the running for the Commissioner post.
Former Fine Gael TD Alan Shatter thinks Mr Harris will be able to call it like it is.
He said: "He should and must be able to operate as the Garda Siochana legislation envisages, as the independent head of the Garda force.
"That incidently means that politicians should keep their sticky fingers out of interfering with garda operational decisions."
The new Garda Commissioner will be allowed to bring in his own team of support staff.
Justice Minister Charlie Flanagan says Mr Harris will be expected to work well with them.
He said: "There may well be an opportunity for the new commissioner to bring with him, a very small number, of support staff, but he will be working with Garda management as a team in An Garda Siochana.
Earlier: The Taoiseach has suggested Sinn Féin is trying to undermine confidence in the new Garda Commissioner after Mary Lou McDonald said Drew Harris will have to prove he will not replicate the 'toxic culture' of the old RUC.
Most politicians welcomed the appointment of senior PSNI officer Drew Harris yesterday.
Sinn Féin's reaction, however, was lukewarm, saying they would hold him to account.
Some in the party have had a strained relationship with Mr Harris during his time in the North and blame him for the arrest of Gerry Adams in relation to the murder of Jean McConville.
"He has to demonstrate that he in no way subscribes to the toxic, vindictive policing culture which necessitated the disbandment of the RUC," said Mary-Lou McDonald.
Sinn Féin Leader @MaryLouMcDonald has called upon the Taoiseach to assure that the new Garda Commissioner Drew Harris will play the part demanded by that office in exposing collusion, uncovering the truth, and holding those responsible to account. pic.twitter.com/KZQFMOTQXV— Sinn Féin (@sinnfeinireland) June 27, 2018
Taoiseach Leo Varadkar took issue with Deputy McDonald's statements, saying: "I am a little bit disappointed by the position that you are taking now which is almost in the space of trying to undermine confidence in the new Garda Commissioner before he has even taken up office.
"I think that is disappointing."
There's also reports this morning the new Commissioner will be allowed to bring in his own management team, which may involve a changing of the guard among garda management.