The Irish Supreme Court has heard that the choice of the new chief of the country is not able to be independent in the role.
Legal proceedings started in a challenge against the former Northern Ireland police (PSNI) Deputy Chief Commissioner Drew Harris was appointed Commissioner of An Garda Siochana.
Ciaran MacAirt, whose grandmother Kathleen Irvine was murdered during The Troubles, brought the action in an attempt to prevent Mr Harris from being assigned to the role.
Mrs. Irvine was one of 15 people killed by loyalists when bombing McGurk's Bar in Belfast in 1971.
Attorney for Mr. MacAirt, Gerard Humphries SC, said there was a clear conflict of interest in Mr. Harris who took the role because he was bound by the official secrecy law in Britain through his work for the RUC, later PSNI, and his role in the historical Questions Team.
They also say that the conflict is incompatible with the tasks of section 5 of the Garda Síochána law, in particular with regard to the security of the state and the investigation of crime.
"Drew Harris can not independently meet the requirements of Garda Siochana due to his involvement in British state security and the Official Secrets Act.
"Any information he might have received on the basis of his position in the PSNI prevents him from fulfilling his duties in this role."
MacAirt, assisted by Kinnear and Co-solicitors with the help of MacGeehin Toale Solicitors in Dublin, has requested permission for a judicial review of the appointment of Mr. Harris.
Recalling the experiences of Mr. Harris in the Historical Inquiries team, Mr. Humphries added that the decisions taken under Harris neglected the measures set out in the European Convention to adequately address cases of collusion.
"In previous roles he failed and he proved to have failed and now he could have the Gardai in his hands."
The former PSNI deputy became the first Irish chief of commission who was appointed from outside the Republic when he was announced as the new commissioner in June.
He will take up the role on September 3rd.
The challenge is challenged by the state and An Garda Síochána, whose legal team is led by Reme Farrell SC, they say that the application does not meet the required threshold and is a personal complaint from the applicant.
"My argument is simply that the application is not readable and is no more than a personal opinion on behalf of the applicant.
"There has been no attempt to tackle the judicial review request, this is nothing more than a series of personal views dressed up as something else.
"An applicant does not have the right to go to court; & # 39; The government has made the wrong decision and I want my opinion on matters to replace the opinion of people in charge of legislative decisions. .. "
Mr Harris is a former Royal Ulster Constabulary (RUC) officer and his officer-father Alwyn was killed in 1989 by an IRA bomb.
After today's talks, MacAirt said it was his right as an Irish citizen to point out flaws in an appointment.
"I have great fears of the basic human rights of Irish citizens when Harris takes charge of An Gardai Siochana, because of what he has done over the last 15 years with regard to victims and survivors of the Troubles.
& # 39; He has brought cases to court and reduced the funds for the police ombudsman, which has disrupted the amount of information that families can get from the police. & # 39;
The McGurk bombardments were one of the worst atrocities of the Troubles and the families of those who died have long campaigned for a new question.
The bombing was carried out by loyalists, but as soon as the security forces blamed the IRA, speculation argued that the dead would have included IRA members who had the device with them.
Campaigners discovered new evidence that was not heard during the original investigation that was held the year after the bombing and rejected a number of committee reports, which they claim to ignore the issue of collusion between government forces and loyalist paramilitaries.
Justice Denis McDonald says he hopes for a court decision on Wednesday morning at 11 o'clock.