Thousands of frontline officers in the country's biggest police force will be equipped with body-worn cameras over the coming months.
Scotland Yard said a large scale deployment of Body Worn Video (BWV) being issued to over 22,000 Metropolitan Police officers starts on Monday.
Cameras will be issued to London's 32 boroughs and to a number of frontline specialist roles, including overt firearms officers. Undercover marksmen are currently unable to use the devices because they are too large.
Last month a survey by the Press Association of forces across the UK revealed a patchy approach to introducing the cameras, with North Yorkshire Police having no plans to adopt body-worn video, and forces including West Mercia and Devon and Cornwall having problems with the technology.
In contrast a string of other forces including the Met, Greater Manchester, Leicestershire, Surrey, City of London and North Wales are among those with plans to use cameras.
Scotland Yard announced it would introduce the devices in the wake of the fatal shooting of Mark Duggan, whose death at the hands of a police marksman in 2011 sparked a wave of unrest that spread across the country.
The force's Commissioner Sir Bernard Hogan-Howe was due to be joined in Lewisham on Monday by London Mayor Sadiq Khan for the roll-out of the cameras following a trial, public consultation and academic evaluation.
The deployment will be managed in a phased approach and is expected to be complete by next summer.
Scotland Yard said: "The technology offers greater transparency for those in front of the camera as well as behind it.
"Londoners can feel reassured during their interactions with the police, whilst allowing us to demonstrate the professionalism of our officers in the many challenging and contentious interactions, such as the use of stop and search."
The cameras will be attached to the officer's uniform and will not be permanently recording.
Police said members of the public will be told as soon as practical that they are being recorded, and when the camera is recording it is highly visible - notable by a flashing red circle in the centre of the camera and a frequent beeping noise when the camera is activated.
Sir Bernard said: "Body Worn Video will support our officers in the many challenging situations they have to deal with, at the same time as building the public's confidence.
"What we do every day will be seen by the public - that has to be good.
"Our experience of using cameras already shows that people are more likely to plead guilty when they know we have captured the incident on a camera. That then speeds up justice, puts offenders behind bars more quickly and most importantly protects potential victims.
"Video captures events in a way that can't be represented on paper in the same detail, a picture paints a thousand words, and it has been shown the mere presence of this type of video can often defuse potentially violent situations without the need for force to be used."
Mr Khan said the technology brings the police force "into the 21st century".
In November 2015, the Mayor's Office for Policing and Crime (MOPAC), awarded a three-year contract worth £3.4 million to Axon Public Safety UK Limited to supply the Met with 22,000 cameras.
Last month, a study by the University of Cambridge found a 93% decrease in complaints made against officers clearly wearing body cameras.