MP Gareth Thomas: 4,000 fewer Met Police officers than in 2010
There are 4,000 fewer police officers working on the front line in London's boroughs than there were two years ago, according to figures released by an MP.
The figures, for March 2010 to April 2012, were obtained by Gareth Thomas, Labour MP for Harrow West.
He said David Cameron needed to explain why London mayor Boris Johnson had allowed so many staff to be axed.
The mayor's office said there would be 2,000 more front line officers in neighbourhoods under current plans.
The BBC has approached Mr Cameron's office for a response.
Mr Thomas gained the figures from the Metropolitan Police Service through a Freedom of Information Act request.
He said they showed the number of front line borough police officers and community police officers had reduced from 25,036 to 20,951.
Mr Thomas said every community in London had fewer police staff than two years ago, and that boroughs had lost an average of over 125 front line police staff.
He said inner-city London had experienced the biggest drop, with Lambeth losing more than 300 officers - a fall of nearly 25% - Southwark losing 222, Lewisham losing 112 and Westminster losing 453.
Mr Thomas said: "David Cameron needs to explain why Boris has allowed so many front line police staff to be axed in London at a time of growing concern about gang crime and over a period that included major riots.
"Back in 2010 David Cameron promised to protect front line police officers, yet quite clearly this is yet another promise he hasn't kept."
A Metropolitan Police (Met) spokeswoman said the force had a total of 33,260 police officers at the end of March 2010 and 32,159 at the end of March 2012.
She said officer numbers fluctuated depending on the number leaving and retiring compared to new recruits.
"In addition, over the last few years the recorded number of officers on individual boroughs has been affected by a number of changes," she said.
"This includes officers who work in some areas such as training who have left boroughs to move to centralised teams or others who remain working on borough but are now recorded as non-borough specific units."
She said the Met was looking at "a range of options" to make £500m savings by April 2015, but that "neighbourhood policing will remain at the heart of our service".
"We are looking to put 2,000 officers back on to the streets and in our neighbourhoods from other roles," she added.
A spokeswoman from the mayor's office for policing and crime said: "These outdated figures ignore the fact that London has bucked the trend of other police forces with a budget settlement that has kept officer numbers high, with about 32,000 cops out on the street fighting crime.
"Budget pressures have led to difficult decisions around cutting backroom staff posts but performance is being maintained and police officer recruitment has been kept up over the last year.
"There will be 2,000 more front line cops in neighbourhoods under current plans and that is the priority for Londoners."