The UK government has set out the terms of reference for an upcoming public inquiry into whether the 1998 Omagh bombing could have been prevented.
Twenty-nine people, including a woman pregnant with twins, were murdered in the dissident republican blast in August that year.
The inquiry will examine whether the authorities had sufficient information and intelligence to disrupt the activities of the bombers in the lead up to the attack.
The British government has called on the Irish government to establish a similar investigation to look at all elements of the cross-border attack.
It is believed the bomb was prepared in the Republic of Ireland and driven to Omagh on the day of the attack.
Several of those linked to the bombing were living in the south at the time.
The UK inquiry was announced in February 2023 by Northern Secretary Chris Heaton Harris and will be chaired by Lord Turnbull KC.
The terms of reference for the inquiry have now been agreed.
They include the assessment of the threat level from dissident republicans between December 1997 and the August 1998 attack, including any change in it after the signing of the Good Friday Agreement in April 1988.
It will also examine the adequacy of the steps taken by the authorities to disrupt those involved in terrorist attacks at the time and whether intelligence sharing could have been better handled, including with the authorities in the Republic of Ireland.
The inquiry will examine a claim made by a former senior investigator in the Omagh investigation, Norman Baxter, that police investigations into two previous attacks in Moira and Banbridge, did not have access to intelligence which could have led to the Omagh attack being thwarted.
It will also focus on intelligence said to have been passed to police in the months leading up to the attack by an alleged police agent Kevin Fulton, which might have been used to prevent the bombing.
The nature of monitoring of vehicles and phones that was available and the analysis of it, will also fall under the spotlight.
The UK government says the inquiry will be able to sit in both closed and open session, depending on the sensitivity of the evidence before it.
Lord Turnbull will report to the Northern Secretary and can choose to produce both an open and a closed report.
In a statement to accompany the publication of the terms of reference he said: “The Inquiry is an entirely independent body. I and my team will decide which are the relevant and important issues to explore and which witnesses will be called.
“We will do so in a manner which is entirely free of influence from the government, or any of the United Kingdom authorities and agencies.”
