Candidates want to start training as soon as possible
The UK's largest police force has implemented a recruitment freeze, forcing 2,000 successful applicants to wait before starting their jobs.
The Metropolitan Police says there are fewer roles because of the "current economic position".
Other forces in England and Wales have also informed candidates they are in the same position.
The revelation comes as police leaders meet to discuss cost-cutting measures, including reducing officer numbers.
The government wants the 43 police forces in England and Wales to find total savings of £545m by 2014.
A spokesman for the 33,000-strong Met said it was considering what to do with the applicants, who are yet to undergo police training.
He said: "We have around 2,000 candidates in the system waiting for a start date.
"This is due to a number of very successful recruitment campaigns last year, coupled with far fewer officers leaving than expected, largely due to the current economic position.
"This has left us with more candidates than vacancies, which is not what we predicted when we embarked on our campaign."
The Met candidates had passed the first stage of the application process and some were awaiting a fitness test and criminal records check when they were told they would not be able to start as early as planned.
Potential recruits have discussed the deferral on the Police Oracle online forum, with several expressing dismay and confusion over their delay in starting work.
One candidate told the BBC their impression was that the different parts of the Met were not communicating with each other and the human resources department was unable to answer many of their questions properly.
They said they had received several letters, each postponing their start date - giving rise to fears that they might have to go through the whole process again as the results they received on the assessment day tended only to be valid for up to a year.
The Met is among several forces that have had to rethink their recruitment plans, although the number of people now on its waiting list is, in some cases, more than the total number of officers some forces employ.
Peter Smyth, chairman of the Metropolitan Police Federation, said he had some sympathy for the force but it was an "unfortunate situation" for those having to wait.
He said: "More people are staying in the Met than ever before... but [the Met Police is] fortunate that many of [the recruits] will be accepted in the next 12 months."
West Midlands Police said it had 240 applicants who had passed all stages of the recruitment process and were waiting for a job, while a further 500 were currently being assessed.
Greater Manchester Police is implementing a complete freeze from April this year.
Avon and Somerset Constabulary said that although it still had vacancies, for the foreseeable future these would only be open to people who had previously applied to that force.
Cleveland Police said although it had a waiting list of 102 successful recruits waiting to be placed, this was normal and not due to economic constraints.
Deputy Chief Constable Derek Bonnard said: "Whilst I recognise the frustration of those who are keenly waiting to join the police service, the process generally takes around 18 months and we are simply aligning anticipated vacancies to our recruit intakes."
The meeting of the police workforce strategy board is looking at proposals to save £400m by ensuring all forces in England and Wales have an equal mix of officers and civilian staff.
West Yorkshire Police also has a recruitment freeze in place
A paper submitted to the board also states that a further £70m could be saved if forces replace managers with constables. It suggests up to £120m could be saved if recruits put themselves through a new accredited course before being accepted into police forces.
Other proposals mooted include the prospect of 28,000 fewer officers in England and Wales as civilian staff take over front-line roles.
The paper - drawn up by Surrey Chief Constable Mark Rowley and Althea Loderick, of the National Policing Improvement Agency - was merely to stimulate discussion, the Association of Chief Police Officers (Acpo) said.