The move came as further details emerged yesterday about the killing of Jean Charles de Menezes at Stockwell Tube station nine days ago, which raise fresh doubts over police claims that he had fled arrest.
Police sources first claimed that Mr Menezes, 27, had run away from officers, leapt over ticket barriers, and had worn a very bulky jacket - making his armed pursuers suspect that he was a potential suicide bomber.
Christopher Wells, a witness to the incident, has now retracted his initial statement that he saw Mr Menezes vault over the ticket barriers. He now believes that the man he saw was probably a police officer pursuing the Brazilian.
A leaked copy of the Met's policy reveals that police are told not to challenge a suspected suicide bomber or shout out "police", in case this causes a device to be detonated. They can also shoot to kill without warning. Last Wednesday, one of the dead man's cousins, Vivien Figuerdo, said she had been told by the family's police liaison officer that Mr Menezes had walked through the ticket barrier, using his pass, wearing an ordinary denim jacket.
Senior Met commanders now admit privately that this discrepancy, and the political backlash over revelations that an official "shoot-to-kill" policy for suicide bombers existed, has very deeply embarrassed the force.
The force has already begun an internal inquiry into the shooting of Mr Menezes, who died from seven close-range shots to the head, but it is now preparing to announce a total review of the strategy.
An investigation already begun by the Independent Police Complaints Commission will also probe how the Met developed the strategy, and its legality, as well as the events before the shooting.