Fine Gael is to consider tabling a private members' motion in the Dail in an attempt to force the Government to hold a public sworn inquiry into allegations of misconduct against gardai in Co Donegal.
Mayo TD Mr Jim Higgins said that once the Dail resumed Fine Gael would move to force a vote on the issue.
It has been confirmed that a chief superintendent from Cork has been appointed to carry out an internal disciplinary inquiry.
Chief Supt Ray McAndrew has brought a team of officers with him to Donegal to conduct the inquiry.
Mr Higgins said it was "farcical and ludicrous" that another inquiry was starting at this stage. In 1999, the Garda Commissioner appointed Assistant Commissioner Kevin Carty to investigate allegations that members of the force had mishandled a murder investigation into the death of Raphoe cattle dealer Mr Richie Barron and had planted explosives.
His report was submitted to the Director of Public Prosecutions nine months ago and to date the only person charged is a civilian accused of making false statements to gardai.
"It is quite obvious that this entire process is going nowhere and the Minister for Justice must now act," Mr Higgins said.
In response to a Dail question last week, Mr Higgins was told by the Minister for Justice Mr O'Donoghue that 12 arrests had been made during the investigation.
Mr O'Donoghue said one person had been charged following directions from the DPP and that "further directions are awaited in respect of other aspects of the investigation".
Mr Higgins said he was concerned because internal Garda investigations were not normally conducted until after criminal proceedings had taken place.
Donegal Division Chief Supt Nacie Rice said he did not believe the internal inquiry taking place would rule out criminal prosecutions.
Chief Supt Rice, who was appointed after his predecessor was transferred by the Garda Commissioner, said the internal disciplinary inquiry was "a normal and natural process" that occurred when a criminal investigation had taken place.
He said a breach of internal regulations could differ from criminal charges but relate to the same set of circumstances.
Mr Higgins said the Justice Minister had given a commitment to hold a sworn public inquiry if he was not satisfied with progress being made.
"It is now quite obvious that a sworn public inquiry is needed," Mr Higgins said.