Paul Scott-Lee said the plans were based on a single force

The government wants to see West Midlands Police merge with West Mercia, Warwickshire and Staffordshire police.

But West Mercia police has begun a legal bid to prevent the merger until further consultation has taken place.

West Midlands Chief Constable Paul Scott-Lee said if West Mercia did not join the proposal would be re-thought.

"Until now, all of our plans have been based on the notion of a Midlands police force that includes West Mercia, Staffordshire, Warwickshire and the West Midlands," said Mr Scott-Lee.

Judicial review

"Now, if the decision was taken that West Mercia was not going to be part of a bigger police force then I think we will go back to the drawing board and start again because all of our plans are designed on creating a single unit for the West Midlands."

The Home Office wants fewer larger forces to tackle serious and organised crime more effectively. Its plan is to reduce the number of forces in England and Wales from 43 to as few as 17.

However, the proposals will not be discussed in Parliament until the autumn, Home Secretary John Reid announced this week.

The West Mercia Police Authority has opposed the merger proposals and began judicial review proceedings this month to try to prevent them being pushed through.

The other three forces have supported the merger move.