A terrorist attack on the City of London is only a matter of time, the police officer responsible for the capital's financial district said on Tuesday.
James Hart, commissioner of the City of London Police, told the Financial Times there had been "hostile reconnaissance" of the City on several occasions since September 11 2001.
"Every successful terrorist group pre-surveys its target. There's no doubt that we've been subject to that surveillance and that sort of thing has been successfully disrupted," he said.
Places staked out included iconic sites, businesses and prominent buildings, "anywhere where the maximum damage can be inflicted on the financial systems of the City of London and [where you can] associate that with mass murder and maximum disruption".
Although the London attacks had prompted businesses to look again at contingency planning, Mr Hart estimated that only 50 per cent of businesses had plans in place.
He blamed chief executives and boards for inadequate contingency planning. London business lobby groups welcomed his comments but said their main concern was the lack of preparedness of small and medium-sized businesses to cope with the economic fall-out of an attack.
Mr Hart said the mindset of would-be terrorists meant the financial centres of western governments were prime targets.
"If you want to hurt the government, hurt people at the same time, and you want to cause maximum disruption . . . where better to hit than at the financial centre?"
He pointed out that the City of London had been the subject of terrorist attacks for three decades. "Look at the number of times we were hit by the IRA. I think [another attack] is a question of when rather than if."
The commissioner said there had been no arrests made as a result of police operations to monitor surveillance activities by terrorist groups, although he added that intelligence agencies would have been sent all information.
Mr Hart adhered to the view that the teams responsible for the London attacks last month were not so much terrorist "cells" as loose affiliations with connections to criminal expertise.
As such, they had no direct or indirect link to al-Qaeda but were a third-tier grouping with intellectual sympathies to al-Qaeda propaganda, he said.
In recent months, the al-Qaeda leadership has stepped up references to economic targets for terrorist activity.
Mr Hart said the the security cordon around the Square Mile had been extended as far as was practicable.
He predicted that although the current climate was in favour of more stringent policing, there would come a point when the public would begin to question the right of the police to use more sophisticated technology to monitor activity.
