Scotland Yard is committed to investing in the frontline of policing in spite of having to find £500 million in savings by 2015, the Metropolitan Police Commissioner has said.
Bernard Hogan-Howe told BBC London that by December the scale and scope of cuts to the force would become clearer and total staff levels could be down to 50,000.
There are 31,853 officers in the Met and the BBC said it understood there were suggestions that up to 6,000 officer posts and 2,000 civilian staff jobs could go by 2015.
Mr Hogan-Howe refused to discuss exact figures but said the force employed 15,000 civilians and 1,900 had already been cut. He would not comment about the number of officer posts under threat.
"We were protected a little this year because of the Olympics, because we wanted to make sure we were kept safe in that very testing time, but by Christmas we will know very clearly where we are going to find the savings over the next few years," he said.
Mr Hogan-Howe said it was possible the force could end up with more constables than ever, even if there were fewer than 50,000 staff overall.
He said: "We are intent on investing in the frontline and making sure that the people who do the job are out there and keeping London safe."
Despite the £500 million savings target he said he believed the force would probably end up more efficient, and a "bit leaner, a bit meaner" while remaining effective.
He said the areas being looked at for possible savings were in management costs, a review of estates across the capital and IT.
Mr Hogan-Howe's interview marks the first anniversary of his appointment as Met Commissioner. He had previously served as acting commissioner following the resignation of Sir Paul Stephenson.
His interview comes after a report published in July by Her Majesty's Inspectorate of Constabulary (HMC) warned that 6,000 officers across the country would be lost from the front line in three years as a result of the Government's budget cuts.
Three forces - including the Met - might not be able to provide an efficient or effective service for the public in the near future, the inspectors warned.
The 43 forces in England and Wales need to close a funding gap of £2.4 billion by 2015 and have plans to make cuts of £2.1 billion, inspectors said.