Relatives of those killed in the Omagh bombing said they are preparing to take legal action over the refusal of the Irish government to establish a public inquiry in the Republic over the 1998 bombing.
A public inquiry, established by the UK Government is already sitting in Northern Ireland.
But the families fear that it will not be able to hold the Irish authorities to account if they're found to be at fault over intelligence failings that allowed the bombing to take place.
After meeting Irish officials in Omagh today, Michael Gallagher, whose son Aiden was killed in the blast said he thought it was inevitable that a legal challenge would now be taken in the Dublin courts.
"I can tell you that some of the law firms have already issued pre-action protocols to notify the Irish government that they're taking the issue to court," he said.
"Our own legal team hasn't done that at this time, but it's probably inevitable that all the core participant solicitors will take an action."
The action is likely to focus on the refusal of the Irish authorities to convene a separate public inquiry in the Republic.
Taoiseach rejects comments on Government co-operation
It comes as Taoiseach Micheál Martin said he rejects comments that the Irish Government co-operation with the Omagh Bombing Inquiry has been "wholly unsatisfactory".
It comes as a barrister representing families of the dead and some of the injured said they remained "greatly disappointed" at the lack of commitment on the part of the Irish authorities to "meaningfully assist" the inquiry.
Mr Martin said that the government is "very committed" to cooperating fully and making material available to the inquiry.
"I don't think it’s fair to make that comment," he said in response to the barrister's comments.
Alan Kane KC was making an opening statement on behalf of the families of eight of those killed in the 1998 bombing and eight of the injured.
He said they remained "greatly disappointed" at the lack of commitment on the part of the Irish authorities to "meaningfully assist" the inquiry.
Later, counsel for another 14 of the families said the credibility of the inquiry rested, at least in part, on the effectiveness of the agreement with the Irish Government through the memorandum of understanding.
Hugh Southey KC said the families he represented continued to press for a parallel public inquiry in the Republic of Ireland.
"It's not yet known if the memorandum of understanding will result in full disclosure of all documentation and the attendance of all relevant witnesses, but this will become clear within a relatively short period of time," he said.
"The victims and survivors that I represent urge the inquiry to keep the effectiveness of the memorandum under review.
"The credibility of the inquiry's work does, at least to some extent, depend on the memorandum of understanding."
Department intention to 'do everything possible'
In a statement the Department of Justice said it was committed to helping in any way it could.
"The Government has made it clear it intention to do everything possible to assist the inquiry.
"The cross border nature of the assistance means this is a complex area, however, the signing of the memorandum of understanding proves that it is possible."
The spokesperson said the department was already dealing with requests from the inquiry and the government remained committed to enacting new legislation if required to facilitate support to the inquiry.
The Government has agreed a memorandum of understanding with the Omagh Inquiry which will see it provide documents from Irish State archives.
But Mr Kane said the families he represented regarded it as "wholly unsatisfactory".
"Our clients wish to use this inquiry to heap shame on the Government of the Republic of Ireland for their failures.
"They consider there is a moral, human and legal imperative on the Government of the Republic of Ireland to establish a parallel inquiry into the deaths of people who were their own citizens, visitors to their country and those who would have been entitled to Irish citizenship under their laws."
Yesterday, lawyers for the PSNI, the Northern Secretary, and the Police Ombudsman for Northern Ireland all made opening statements to the inquiry.
It was made clear that the pace of discovery of documents was slow due to the fact that any digital files available were held on antiquated computer systems and in many cases searches had to be conducted by hand in physical archives.
Mr Southey later said effective disruption of the Omagh bombing potentially require the assistance of the Irish authorities.
He said his clients wanted the Irish Government to establish a procedure that would enable findings to be reached regarding any failings that may have occurred within the jurisdiction of the Republic of Ireland.
He said it appeared that information had been available to the gardai that had not been passed to the RUC.
The Omagh Bomb Investigation Team briefed families in 2008 during which they told them intelligence material showed that dissident republicans had discussed police and army bases in Omagh in November 1997.
That briefing document had stated: "The information was not passed onto the RUC, and therefore the sub-divisional commander in Omagh was not made aware of this information regarding the military bases or his own station.
"The Investigation Team assessed that this information should have been passed onto the RUC at that time bearing in mind the number of terrorist bombs and attempted bombs in 1997.
The same briefing document said that, in addition, after an operation by the Garda in April 1998 to disrupt a dissident operation, a generalised document was provided to the RUC that lacked sufficient detail.
Twenty-nine people were killed, including a woman pregnant with twins, when the Real IRA detonated a car bomb in Omagh's main street on August 1998.
Mr Kane said there were a host of issues arising in the Republic which needed to be fully addressed at the inquiry, including the actions of agents there, information provided by a garda whistleblower and the adequacy of various investigations that had been carried out.
And he questioned the ability of the memorandum to deliver the candour his clients wanted.
He said the mechanism whereby the Irish authorities would supply documents which it considered relevant and which related purely to any failures by the UK authorities was a "significant escape clause" for the Republic.
He said that was compounded by the retained right to redact Irish documents before sending them to the inquiry.
None of this instilled confidence, he said.
"I have the authority of those I represent to say that they are sick and tired of platitudes, false assurances, broken promises and the grand but empty words from the State authorities of the Republic of Ireland.
"Their resolute refusal to institute a parallel inquiry and their ongoing failure to provide real and meaningful co-operation with this inquiry speaks far louder than their words."
