Mayor of London Boris Johnson has lifted a recruitment freeze at the Metropolitan Police and said an extra £42m funding would mean an increase in police numbers.
Police forces across the UK face up to 20% budget cuts. The Met's recruitment freeze began in September 2009.
Mr Johnson it would mean there were more police than at his 2008 election.
The Met welcomed the funds. But Labour claimed Ken Livingstone's final budget as mayor would have seen more officers.
The latest figures show there are 32,481 officers policing the capital.
Mr Johnson says the extra funding will mean 32,510 full time officers on the streets of London by May 2012.
But police projections suggest the number of officers is likely to subsequently fall to 31,913 by April 2013, and then to 31,800 by 2014.
Former mayor Ken Livingstone claims his final budget funded 32,610 police officers in London.
Mr Johnson revealed the plans at a six-hour budget debate in City Hall.
He said: "I believe we can go further in bearing down on crime so in my budget I am proposing to increase funding for the Met by £42m.
"This investment means that as of next week we are starting up recruitment again for the Met in order to reach a target of 32,510 full time warranted police officers.
"By the end of my first term of office London will have significantly more police officers that I inherited in 2008."
Home Office minister Nick Herbert added: "In the week when shrill voices were claiming spending reductions would damage policing, Boris has spectacularly proved them wrong."
But a spokesman for Mr Livingstone, who is standing against Mr Johnson in the 2012 mayoral election, said: "Boris Johnson's approach to funding the police is characterised by a smoke and mirrors approach, trying to obscure real cuts to police funding.
"The reality is after four years under Boris Johnson there will be less police in London than there were under the budgets delivered by Ken Livingstone."
The Met has been trying to save £163m from its £3.6bn budget.
A spokesman said: "The additional funding that has been secured for policing is great news for the Metropolitan Police Service and the public and it means that the cuts to the budget are significantly reduced.
"This investment will allow some police officer recruitment, enabling us to retain significant police numbers."
The Met said the money meant 200 PCSOs who had been selected to become Pcs before the freeze could now complete their training.
Metropolitan Police Federation chairman Peter Smyth said: "Mr Johnson's announcement that recruitment is to start again is excellent news.
"A significant fall in police numbers would have put at risk the reductions in crime which have been achieved in recent years."