Compulsory police retirement 'affects 3,200'
As many as 3,200 police officers could lose their jobs if every force in England and Wales introduced compulsory retirement.
The figures were revealed in a Parliamentary answer from Theresa May, in response to a question from her Labour shadow, Ed Balls.
The compulsory retirement rule is for those with 30 years' service and would be used to cut police costs.
At least three police authorities have agreed in principle to use the rule.
These include Strathclyde in Scotland, while Greater Manchester Police has said this week that it too intended to use the rule, known as Regulation A19.
In total, there are 3,260 officers with more than 30 years' service in England and Wales - including 1,154 in the Metropolitan Police, 244 in the British Transport Police, 198 in the West Midlands, 126 in West Yorkshire and 122 in Merseyside.
The Metropolitan Police Commissioner, Sir Paul Stephenson, has said his force will not use A19 - but even without the Met the total is still more than 2,000.
According to the BBC's Danny Shaw, the issue of police cuts dominated the first part of Prime Minister's Questions, as Harriet Harman challenged David Cameron.
Ms Harman, standing in for Labour leader Ed Miliband following the birth of his son, questioned why £100m was being spent on the new elected police commissioners while police forces were being forced to make cuts of 20%.
Mr Cameron insisted that elected commissioners would improve accountability and that cuts to "bureaucracy" would help free up officers' time.Commons clash
Ms Harman asked Mr Cameron to "tell the House how many fewer police officers there will be as a result of his 20% real terms cut in the police budget".
Mr Cameron said it would be up to "individual police forces... to try and make sure they maximise the resources on the front line.
"What we said in the spending review is it is possible to keep the high level of visibility and activity of police on our streets.
"That is the challenge to every police force in our country and I think, when you look across police forces and you see how many officers there are in HR and in IT and in back office functions, I think we can succeed in this."
In a separate development, police staff associations in England, Wales, Scotland and Northern Ireland say proposals for forces on the UK mainland to be used to support colleagues in the Police Service of Northern Ireland (PSNI) in public order situations are "not feasible".
Reductions in police numbers in Northern Ireland have prompted discussions between the PSNI, Northumbria, Strathclyde, West Yorkshire and South Yorkshire forces.
Representatives from the forces are due to meet next week to discuss a "memorandum of understanding" over the issue of mutual aid.
The Police Federation of England and Wales point out that PSNI officers are routinely armed and, although officers from the mainland already provide specialist help in other areas, public order situations in Northern Ireland require "specialist skills" and can lead to "very volatile and demanding circumstances".