Thousands of workers in Northern Ireland have been trained to battle the threat from al-Qaeda and dissident killers.

They include shop managers, security guards and hotel employees — meaning anyone from the Europa Hotel to Victoria Square could be on the hunt for Islamic extremists and rogue republicans.

Spooks picked them out because they are in front-line jobs dealing with large crowds where terrorists conceal themselves as they scout high-profile venues for gun and bomb attacks.

The workers are among 60,000 staff across Britain who have been taught how to monitor suspicious behaviour in what the National Counter Terrorism Security Office warns are “mass-casualty” businesses.

A Home Office spokeswoman said: “Thousands of employees in Northern Ireland have been trained as part of the strategy. We will not put an exact number on it for security reasons, but it is in the thousands.”

Security sources revealed that even though the scheme was aimed mainly at combating al-Qaeda across the UK, it was vital it was in place in Northern Ireland in the wake of the dissident outrages in March.

“The dissident threat is mentioned in the new report as one of the elements that makes monitoring terrorism key to public safety today,” one said.

“It is more important than ever now that everyone, including the public, keeps their ear to the ground and can give tips to help stop future atrocities.”

“Spy” training for the workers was at the centre of a Government anti-terror strategy unveiled earlier this year.

The initiative — called Contest Two — updates the Contest strategy developed by the Home Office in 2003.

Contest Two warns that a “dirty bomb” attack on

Britain is highly likely and names the biggest threat to the UK as al-Qaeda-linked groups.

Government officials hailed the project as one of the most comprehensive approaches to tackling the threat issued by any government in the world.

The Contest report was released in March — two weeks after the Massereene army barracks massacre in Antrim when sappers Patrick Azimkar and Mark Quinsey were gunned down by rogue republicans.

Forty-eight hours later, PC Stephen Carroll was blasted to death by a Continuity IRA sniper while answering a distress call from a terrified woman.

The terrorism threat level, set by the Joint Terrorism Analysis Centre, has been “severe” since July 2007, which means that future terrorist attacks are highly likely but not thought to be imminent.

Home Secretary Jacqui Smith said the “widest range” of people had been enlisted to battle terror because police, security and intelligence agencies could not be “solely” relied upon to tackle the threat.

She identified “shopping centre managers, store managers, people who were responsible for the security in those areas” as being key in fighting terrorism.

Prime Minister Gordon Brown said when Contest Two was released: “Tens of thousands of men and women throughout Britain — from security guards to store managers — have now been trained and equipped to deal with an incident.

“They know what to watch for as people go about their daily business in crowded places such as stations, airports, shopping centres and sports grounds.” He added there was a “duty on all of us” to stand up to people who advocate violence and preach hate.

Human rights groups have hit out at the move, saying it could encroach on civil liberties.

One source said: “Does this mean that shop managers can now get a GNVQ in anti-terrorism? It’s ridiculous. Putting the power to monitor the public like this is very dangerous when placed outside the hands of the law.”

Contest Two could also see official funding withdrawn from organisations that flirt with extremism — even

if they remain within the letter of the law. By 2011, Britain will be spending £3.5bn a year on counter-terrorism.

The number of police deployed on counter-terror work has risen since 2003 from 1,700 to 3,000, while the security service MI5 has doubled in size over the same period. Between 2001 and 2008, almost 200 people have been convicted of terror-related offences.