HOME Secretary David Blunkett is being pressed to scrap the merger of Huddersfield and Dewsbury police divisions.
The call was made as opposition mounts to the plan.
Link-up proposals recommended by the West Yorkshire Police Authority are due to be rubber-stamped at a meeting next week.
Clr Robert Light, leader of the Tories on Kirklees Council, said the move would do nothing to improve policing.
It would lead to lower standards of policing and make the police force seem more remote, he added.
In a letter to Mr Blunkett, Clr Light said: "Kirklees is geographically split into north and south - two entirely separate communities with very different policing requirements.
"A merged Kirklees police division will not, in our opinion, be able to deliver the local knowledge and expertise required by these diverse communities."
Clr Light said it was vital that Mr Blunkett halted the plan.
The merger is due to be approved by the police authority's best value review committee on Friday next week.
Opponents are holding a public meeting in Dewsbury next Monday to make their voice heard.
Clr Light says in his letter: "I am also disappointed at the lack of consultation that has taken place over this matter.
"I feel the decision has been shrouded in secrecy.
I find this to be unacceptable, when local government and public services are trying to become more accountable and transparent."
A police authority spokes- man said the merger was a change in management structure and would increase the number of officers available for local policing.