Police services in the Midlands face a major shake up after an official review warned smaller forces are unfit to meet the challenge of organised crime and terrorism.
The Warwickshire, Staffordshire and West Mercia forces all face being merged or replaced.
An inquiry by Her Majesty's Inspectorate of Constabulary (HMIC), chaired by Denis O'Connor, former Chief Constable of Surrey, concluded that smaller forces with fewer than 4,000 officers "fall someway short" of the standards expected of them.
Charles Clarke, the Home Secretary, has summoned chief constables to meet him in London on Monday, to discuss the findings.
It means every one of the region's emergency services is in the midst of major changes.
Earlier this week, The Birmingham Post revealed health authorities were planning to replace existing ambulance services with one region-wide service.
And local fire control rooms will also be axed, to be replaced by one West Midland service.
The long-awaited HMIC report said: "Size matters - larger forces are likely to have much greater capability and resilience whilst smaller forces, in many cases, find it hard to provide the services to an acceptable standard."
Inspectors had conducted detailed investigations into all 43 forces in the country, the report says.
It warned: "Vulnerability was evident in relation to counter terrorism and domestic extremism, serious and organised crime and public order."
Forces with more than 4,000 officers, or 6,000 staff including police and civilians, tended to be far more successful.
But the report warns: "Forces below that size tended to fall someway short of the standard, with, in general, the smallest forces faring the least well."
Warwickshire Police employs 1,012 officers, while Staffordshire Police employs 2,309 and West Mercia Police, which covers Herefordshire, Worcestershire and Shropshire, employs 2,380.
West Midlands Police employs 8,154 officers, but could still be affected by the changes if it is asked to merge with another force.
Mr O'Connor said he was recommending the creation of new "strategic forces", which would be formed by merging existing forces.
But there were fears in the region that local services would suffer as a result.
Phil Blundell, chair of Warwickshire Police Authority, said he would raise concerns with Mr Clarke.
He said: "Policing in Warwickshire is owned by local people, and they know who their local bobbies are.
"One of the fears is that this will be another service lost to a big amorphous centre."
Warwickshire County councillor Richard Hobbs, portfolio holder for community safety, said: "We realise that Warwickshire Police is a comparatively small force but that should not be a criterion for amalgamation.
"We feel that the make-up of the county, with its mixture of rural and urban areas, needs a particular kind of policing; one where the officers are familiar with the area and its own particular issues.
"We will fight to make sure that this is the kind of policing that Warwickshire's residents receive."
Warwickshire MP Jeremy Wright (Con Rugby & Kenilworth) said: "I will be waiting to hear what Charles Clarke says on Monday, but what would be a concern is resources being concentrated on urban areas at the expense of rural areas."