A British judge has called on the UK and Irish governments to hold inquiries into the 1998 Omagh bombing by Irish nationalists after concluding there had been a “real prospect” of preventing an attack that killed 29 people. Eight years ago, families of the victims challenged the UK government’s refusal to hold a public inquiry after commissioning a report that concluded that key evidence about the bomb plot was either missed or not passed on. Mr Justice Horner on Friday stopped short of calling for the public inquiry demanded by many of the families into the worst single atrocity of the Northern Ireland conflict, known as the Troubles. But he said the two governments should investigate whether a more proactive security approach could have thwarted the terrorists. The attack in the Northern Irish town came four months after the Good Friday Peace Agreement was signed that largely brought peace to the island of Ireland after three decades of civil strife. The Omagh attack was carried out by dissidents opposed to the agreement. In his long-anticipated judgment delivered at a court in Belfast, Mr Justice Horner said: “I am satisfied that certain grounds when considered separately or together give rise to plausible allegations that there was a real prospect of preventing the Omagh bombing.” Michael Gallagher, whose son was killed in the blast, launched the review in 2013. The report he and other families commissioned drew on hundreds of pages of emails between David Rupert – an American trucker-turned-informant who infiltrated republican paramilitaries – and his handler from the British security agency MI5. It is understood the emails provided detail on potential planning, locations and personnel for an attack in the run-up to the blast on August 15, 1998, when a stolen Vauxhall car was packed with 500lb of explosives and detonated in the town centre. The families say those details were not shared with police on either side of the border before the attack or during the investigation to find out who was responsible. The families believe the Rupert emails, along with warnings of a dissident operation from an agent for British military intelligence and an anonymous tip-off 11 days before the attack naming three men, should have prompted a security operation in Omagh that could have prevented the attack. Copies of the emails were obtained by the families, and sections were used in a civil case which saw them win £1.6m ($2.2m) in 2009 against four men found liable for the murders. Mr Gallagher welcomed the ruling on Friday and said the families’ campaign had been vindicated. “We knew … that this was a preventable atrocity, but it's one thing for me to say it, it's an entirely different thing for a senior High Court judge to,” he said. The UK government said it would consider the judgment before announcing its next step. The Northern Ireland Secretary Brandon Lewis said: “We recognise that today the court has set out that there are 'plausible allegations that there was a real prospect of preventing the Omagh bombing' and that more should be done to investigate this.” The Irish government said that it would "do what was necessary" following the ruling. Jason McCue, a lawyer who has campaigned for justice of victims of Irish republican violence but was not involved in the action, said: “The families deserve the truth and justice. Their determined and persistent fight for such should be applauded. Today was another significant step.” The attack in Omagh was carried out using a massive fertiliser bomb. No one has ever been convicted. Republican factions had for years had received material and support from the Libyan regime of Muammar Qaddafi, including Semtex that was used in other high-profile attacks. <br/>