Omagh Bomb campaigner Michael Gallagher says it would be 'a scandal' if the Irish government gagged him as it did to Kingsmills Massacre victims

He was speaking after Irish Tanaiste Michael Martin gave assurances this week that Dublin would be "fully cooperative" with a public inquiry in Belfast into the bombing.

Mr Martin was speaking after once again ruling out Irish authorities holding their own inquiry into the atrocity - as was recommended by the High Court in Belfast.

The terms of reference for the Belfast inquiry were published on Wednesday.

In 2015 then Taoiseach Enda Kenny visited Bessbrook where he made an almost identical promise of full cooperation to another group of victims of a cross-border terror attack.

They were the families of the Kingsmills Massacre; In 1976 the IRA gunned down ten Protestant workmen in south Armagh in an attack which had been planned and executed from the Republic of Ireland - just like the Omagh Bombing.

However, after almost a decade of unrelenting pressure for answers, the Kingsmills families were ultimately gagged from publishing what responses Gardai finally gave to their questions about the atrocity.

After almost ten years of requests, Gardai finally gave evidence in a secret court hearing in Dublin in March. Neither the Kingsmills families, their lawyers nor the media were allowed to attend.

A summary of Gardai answers was later given to the Kingsmills families – but they are gagged by specially drafted Irish legislation from ever disclosing it.

Michael Gallagher says he will hold Dublin fully to account.

"I was aware of the difficulties that the Kingsmills families had in getting cooperation from the Irish government," he told he News Letter. "It was shameful because this is the government that holds the British government to account on every occasion. And yet, here, when the tables are turned on them, they're not too keen to cooperate.

"I do think that's scandalous that they have basically tied the Kingsmills families down to not being in a position to comment on what the Gardai knows about Kingsmills.

"We know what the Irish government is capable of. We have got the British government, who did put the victims to the forefront. But the Irish government are dragging their feet and I think we need to test them and we will hold them to account.

"I was not aware of what they did on Kingsmills behind closed doors. But that would not be the kind of inquiry we would want. That would be a scandal. And victims deserve the truth."

Meanwhile, former Police Ombudsman Baroness Nuala O'Loan has also put pressure on the Irish government to hold its own inquiry into the Omagh Bombing.

"We cannot compel them to hold an inquiry but it would undoubtedly be very beneficial if they had a sitting inquiry with corresponding powers to that which this (UK) inquiry will have,” she told the BBC on Thursday.

"If there were a parallel inquiry running in the Republic of Ireland, it would be most useful.

"If they have an inquiry running which had the powers to extract from their authority, largely An Garda Síochána (Irish police), the information and intelligence which was held - that would be very good".

Baroness O'Loan, who investigated the police's actions in the lead-up to the bombing, has previously claimed the Omagh attack could have been prevented if the security forces had acted differently.

Kenny Donaldson, director of victims group SEFF, also expressed very low confidence in the Irish government.

"There is little-to-no confidence amongst those Omagh families we support – and others impacted by cross-border terrorism – that the Irish Government will act appropriately on these matters,” he said.

"There is absolutely a need for an Inquiry be held within their jurisdiction given the weighted connection of that jurisdiction in terms of not only the Omagh case, but also other bombings carried out within the 12–18-month period leading up to Omagh.

"The Irish Government have not been prepared to have a spotlight shone on the role they played and/or didn't play in this case, and so many others.

" If this position persists then legal challenges may require to be taken. Otherwise, an outcome lacking integrity is likely to follow which does nothing in pursuance of the natural principles of justice and of fairness".

Invited to comment on the conduct of Dublin, a spokesman for the Northern Ireland Office said: "We will continue to raise this matter with the Irish Government."

On Wednesday Secretary of State Chris Heaton Harris challenged Dublin to explain itself over Omagh.

He said: “I urge the Irish Government to now explain what consideration it has given to the setting up of an investigation in Ireland to discharge its obligations under Article 2 of the European Convention on Human Rights, in line with the clear direction of the High Court.”

Also on Wednesday, former First Minister Arlene Foster spoke out on the same issue.

She said the Terms of Reference for the Belfast Omagh Bomb Inquiry "again highlight the need for a parallel public enquiry in the Republic of Ireland and the scandalous decision by the Irish Government not to hold one”.

She added: “Our Government should NOT let this slide but instead take a case against the Irish Government for their neglect and obfuscation.”

The Irish Department of Justice responded that the Irish Government is “anxious to ensure as far as possible, that by the end of the UK inquiry, there are no unanswered questions relating to the Omagh bombing that can only be examined in this State”.

It added: “The Minister, in consultation with her Cabinet Colleagues, will keep under consideration what further action may be required in this jurisdiction.

"Officials here have already been engaging with the inquiry team and look forward to continuing this engagement as the Inquiry now officially begins its work.”