Police force mergers have been delayed by the Home Secretary

The force, which covers Worcestershire, Herefordshire and Shropshire has strongly objected to the merger.

Under the plan it would join the Warwickshire, Staffordshire and West Midlands Police to create one force.

Police minister Tony McNulty said there was a chance West Mercia could stand alone and work closely with the others.

The Home Office wants to reduce the number of police forces in England and Wales from 43 to as few as 17.

Trial period

It said larger forces were needed to properly combat the threats of terrorism and organised crime.

Under its original proposal the four forces in the West Midlands region would create one "super-force".

I think we will go back to the drawing board Paul Scott-Lee, Chief Constable West Midlands Police Warning over merger plan

But Mr McNulty said in an interview with the BBC's Politics Show: "There may be some configuration that says Staffordshire, Warwickshire and the West Midlands go ahead.

"West Mercia have to show to me in very very strong detail how across the region they can meet the concerns about protective services and more serious crime in some kind of joint federation with the merged force of three."

He said the system could be trialled for two or three years.

"If that worked it may be sustainable, if it didn't then the quid pro quo would be to merge it with everybody else."

It is the first time the government has hinted at allowing a stand alone West Mercia force.

Mergers 'way forward'

Mr McNulty's comment come just days after West Midlands' Chief Constable Paul Scott-Lee said the merger plans would have to be completely re-thought if West Mercia did not join the other three.

Mr Scott-Lee said: "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."

We have said very clearly that 43 forces in the country is not the way to go forward Tony McNulty, police minister

Mr McNulty agreed it was a problem but said: "I have said to West Mercia almost 'show us your cards now' if you think you can better deliver for the West Mercia and contribute to the overall West Midlands region."

On Monday the government said the merger plans would not be pushed through before parliament's summer recess on 25 July.

But Mr McNulty said the Home Office was still committed to reducing the number of forces across England and Wales.

"We have said very clearly that 43 forces in the country is not the way to go forward.

"People have raised very good concerns about finance, about council tax, about governance and a whole range of other issues and I have asked everybody to take this time now to really look in some details at these matters and go forward."

Earlier this month the West Mercia force launched a legal bid to delay the merger plan before further consultation.