Police representatives from Kent, Surrey and Sussex are lobbying MPs over Home Office proposals which could see the three forces merged into one.
Sussex Police said it did not want to be rushed into a merger
The south-east forces oppose any merger plans, preferring instead to work more closely on policing initiatives like organised crime and counter-terrorism.
A national lobby day is being led by the Association of Police Authorities.
A plan was announced in November to see if the 43 police forces in England and Wales could be reduced to 12.
The lobbying day at Parliament on Wednesday is part of an attempt to force the home secretary into a rethink.
Anne Barnes, chair of the Kent Police Authority, said she was willing to buy breakfast for Charles Clarke if he would visit the county "to listen to what we have to say".
Kent Police wants to remain as a stand-alone force
"There are some forces which are too small, and for the best service they think they should be merged. But we are not one of them."
Ms Barnes said £58m would be needed in start-up costs alone for a merger with the neighbouring Surrey and Sussex forces.
Surrey Police is equally concerned about the financial implications.
Chief Constable Bob Quick said: "It will cost an additional £26m per year to achieve full resilience in Surrey as a stand-alone force, whereas it will cost £29m, with ongoing revenue implications, to merge with Sussex."
Surrey Police Authority chair Liz Campbell added: "We are asking Surrey MPs for their backing in a bid to move the government emphasis away from restructuring to tackle the real issue of how police resources are used and funded."
Sussex Police has also said it cannot support any of the merger options in the South East.