A Midland chief constable yesterday described Government plans to reorganise forces as "scandalous" and a "major diversion" to normal police business.
West Mercia Chief Constable Paul West spoke out after his police authority voted to reject Government proposals that will create a single Midland regional service.
It is opposed to joining West Midlands, Warwickshire and Staffordshire constabularies, and believes it can reinvent itself as a "strategic police service" in its own right.
Yesterday it declared its business case to the Home Office, outlining plans to recruit additional officers to enable it to meet Government standards in fighting cross-border criminality, such as organised crime and terrorism.
The plan will almost certainly spark a dispute between West Mercia and the other three Midland police authorities, which favour the regional super-force model.
The Government plans will be delayed for more than a year if "forced amalgamation" is launched in regions where police authorities oppose it.
West Mercia's proposals come at the end of a threemonth consultation period which began when proposals to reduce the existing 43 forces nationwide to just 20 were announced.
Mr West said: "I think the timescale has been scandalous - to re-configure the entire future of British police in a matter of weeks.
"Certainly, the message is coming from the Home Office now that they appear to be taking a rather more measured approach to the responses that police authorities have, and not just this police authority, many police authorities up and down the country.
"But the pressure that has been placed has been very unreasonable. It has been a major diversion from normal day-to-day business for all of us.
He said West Mercia was "serious" about reforming, adding: "I would certainly hope the Home Secretary would realise we are doing what we strongly believe is best for our communities."
The police service was instructed by Home Secretary Charles Clarke to consider change after a report concluded in September that the 43-force structure was no longer "fit for purpose".
According to a report by Her Majesty's Inspectorate of Constabulary, forces with more than 4,000 officers tend to be far more successful.
West Midlands Police meets the Home Office's requirements, as it employs 8,154 officers. Warwickshire Police employs just 1,012, Staffordshire Police 2,309, and West Mercia - which covers Herefordshire, Worcestershire and Shropshire - has 2,380 officers.
Mr West said "The decision that this authority has taken is based on the most comprehensive consultation exercise that this police force has undertaken and probably the most comprehensive of all police forces."
In the unlikely event that West Mercia's proposals are accepted by its three neighbouring forces, a new structure could be put in place by April 2007 if the Home Secretary agrees.
However, a dispute will lead to further consultation being held before the Government forces "amalgamation orders" through Parliament.