Just half of British businesses have contingency plans for coping with a terrorist attack or other emergency, it has emerged, amid warnings that it is only a matter of time before terrorists try to attack London's financial institutions.
James Hart, commissioner of the City of London Police, told The Financial Times newspaper that there had been "hostile reconnaissance" of the City since the September 11 attacks in 2001.
He said: "Every successful terrorist group pre-surveys its target. There's no doubt we've been subject to that surveillance and that sort of thing has been successfully disrupted.
He added the area had been a terrorist target for three decades, saying: "Look at the number of time we were hit by the IRA. I think (another attack) is a question of when rather than if."
Potential targets included businesses and prominent buildings in London Square Mile, in fact "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".
Just 50 per cent of businesses had contingency plans in place in case of an attack, he calculated.
"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 said.
The security "ring of steel" has been extended twice since 9/11 but businesses and workers are being advised to remain vigilant in the wake of the July 7 and July 21 attacks.
In the past the City was targeted by the IRA, with three people killed in April 1992 when a bomb exploded outside the Baltic Exchange and one person killed in April 1993 when a bomb targeted the Bishopsgate area.
Businesses outside the City were targeted in 1996, when a large bomb was detonated in the Docklands.
The CBI told the BBC today that it is often simply insufficient time and money that prevents smaller firms from developing contingency plans.
It has called for expert advice and tax breaks to be provided to the companies to encourage them to put contingency plans in place.
Business lobby group London First, meanwhile, has estimated that half of companies are unprepared for a significant event, with small and medium companies particularly vulnerable.