Directly elected police and crime commissioners will cost £100m more than the current system over the next five years – the equivalent of 600 police officers' jobs, the Association of Police Authorities claims.
The APA, which represents the authorities that will be replaced by the commissioners under the plans, said it was "unconvinced that this is a price the public are willing to pay".
It added that Ipsos MORI research showed the public did not want any individuals responsible for policing to have an "obvious political allegiance".
Rob Garnham, chairman of the APA, said: "Police authorities are not convinced that there is a public appetite for the significant changes to police governance currently being proposed by the Government, including the introduction of police and crime commissioners."
He said he was concerned the Government had failed to identify the costs of introducing the commissioners at a time of financial crisis.
"It is imperative to understand what the costs will be, so that everyone can be sure the benefit derived from any changes outweighs the costs," he said.
A cost analysis from Boxwood Consulting, commissioned by the APA, found that the new structure of directly elected commissioners and local police and crime panels would cost £453m over the five years from 2011-12, based on current assumptions. This involved a four-yearly election cost of £64m and transition costs of £12m, it said.
The existing police authorities would cost £352m, with only one election in the five-year period, a difference of £101m.
"Police authorities remain unconvinced that this is a price the public are willing to pay for changes that would see oversight of policing move to the hands of a single individual," Mr Garnham said.
But he agreed that there was "much to do to improve policing across England, Wales and Northern Ireland to ensure that the service continues to meet the requirements of communities in the 21st century".
The Ipsos MORI researchers, commissioned by the APA, carried out workshops in each police force area in August and found a "strong preference for a visible and named figurehead for police accountability in each area".
But this should not be someone with "an obvious political allegiance", the researchers found.Reuse content