The Chief Constables of two police forces today defended the "transformational" changes which could result following a meeting with private sector firms to discuss the possible contracting out of some work by the forces.
The chiefs of West Midlands and Surrey Police spoke after a conference in London for the private sector to find out more about the possibility of working with police forces.
Chris Sims, chief constable of West Midlands Police said: "The proposition is: let us bring a commercial partner who could bring expertise, bring experience, bring technology that will allow us to transform how we do things and allow us to bring a better service to the public.
"We are very, very aware that this is an emotive subject. Very aware that this can be presented in terms of language like outsourcing and privatisation - it isn't that.
"Be under no doubt that for Surrey and West Midlands Police, direction and control of police officers can only remain under the chief constable and, through the PCC, be accountable to the public."
Mr Sims was speaking after the meeting attended by 120 business delegates at London's Congress Centre, who heard the chief constables outline what they hoped to achieve from such partnerships.
The plans are opposed by trade unions, and members of two unions staged a protest outside the conference earlier in the day.
Earlier this month former deputy prime minister Lord Prescott launched a campaign to "keep the police public", warning that bringing in private security firms could lead to the privatisation of bobbies on the beat.
Mr Sims said that other forces would have the opportunity to take part, and said that many forces were represented at today's conference.
"We are in this to improve service, we are not simply looking for a way to do the same thing for less money," he added.
The chief constable of Surrey Police, Lynne Owens, said: "We are both really proud to be police officers, and because we have operated on the front line we both understand the responsibilities of a front line officer. There will be some roles that are never ever subject to this privatisation/joint venture requirement.
"All we have done today is have a meeting with a private group of people and said: 'This is how we are thinking. You tell us what it is you can do'.
"We don't know whether they are going to be up for it. At the moment this is not a game-changer. We are at a very early stage of a long process."
The officers added that up to half of "back-office" staff may be cut over the next four years as part of cost savings measures.
The tender process is expected to take until spring next year with contracts running for seven to 10 years and are expected to be worth up to £1.5 billion.
The Unite and Unison unions protested against the plans outside the Congress Centre earlier in the day.
Peter Allenson, a national official at Unite, said: "There is no business case for either the government or the police forces to go down this route.
"Clearly the government are looking to make savings, but this could be an enormous white elephant.
"We believe any savings will be made at the cost of proper local policing and our members' terms of employment."
Asked about the possibility of strike action he said: "Nothing is being ruled out and we will look at our traditional routes when considering the next steps. Of course, the ultimate decision would be down to our members.
"We will also look at going down the political route. A number of the constituencies in the West Midlands are marginals, so there will be a political campaign. We will also ask for assurances from candidates in the police commissioner elections."
Lord Prescott, who intends to stand for election as a Police and Crime Commissioner (PCC) in Humberside, wants a public debate on how far the public are prepared to see private firms involved in policing.
He said this month that it was "extremely alarming" that the two forces were asking security firms to bid for contracts to run some services that are currently carried out by officers.