Protesters denouncing economic inequality have been camped outside London's landmark St Paul's cathedral since October as part of an international movement inspired by the Occupy Wall Street protest.

Home Secretary Theresa May said that along with terrorism and organised crime, disruption from protests was one of the biggest threats to the Olympics which begin in July and wants London 2012 organisers (LOCOG) to use "all available" powers to remove equipment and encampments, rapidly backed up by police.

"We have seen in recent months encampments taking place around London and elsewhere," May told reporters.

"I think it is right that we said to ourselves 'do we need to do anything extra in relation to the Olympics to ensure we can strengthen our policy to deal with this?'"

However, LOCOG said it was likely that tents would only be on their restricted rather than prohibited list, meaning tents could be allowed on to venues but not erected.

Britain's National Olympic Security Coordinator Chris Allison said last week the global attention on the Games, with May saying some 4 billion people worldwide would watch on television, would make it attractive to protesters.

However, police have insisted they had no intention of preventing any legal demonstrations outside Olympic venues.

At a conference on Olympic security in London, May also warned there was a strong possibility the Games would be a target for cyber criminals and "hacktivist" groups.

"These groups may attempt to target the Games and may also attack the websites of high-profile sponsors associated with the Games," she said, also disclosing 97 people had been arrested by police targeting crimes such as ticket touting.

The Olympics will be Britain's biggest peacetime security operation, likely to cost more than 1 billion pounds, with some 23,700 guards at venues, made up of staff from private security firm G4S, volunteers and military personnel.

Security officials at Wednesday's conference again insisted there was no specific intelligence indicating any threat to the Olympics.

Britain is currently on its third highest alert level of "substantial", meaning a terrorism attack is a strong possibility but this will almost certainly be raised to "severe", indicating an attack is highly likely, by the time the Games begin.

Britain has been a target for Islamist militants for the last decade as an ally for U.S.-led military action in Afghanistan and Iraq and London suffered its worst peacetime attack in 2005 when four suicide bombers killed 52 commuters.

(Reporting by Michael Holden)

• A Permanent Economic Emergency