West Mercia's chief constable Anthony Bangham and the area's Police & Crime Commissioner John Campion have responded to concerns expressed by their Warwickshire counterparts over the end of the two force's alliance.
In a statement responding to the concerns raised recently, the two have said: "The decision to end the Strategic Alliance with Warwickshire followed prolonged efforts to reform the arrangement.
"When it became clear that was not going to be possible, the only viable option available was to terminate.
"This decision was taken following detailed analysis of the implications for our communities and our police force.
"That analysis confirms quite clearly that the current arrangement is no longer in West Mercia’s interests.
"The Alliance did deliver some benefits in its early days.
"However, as the organisations reformed and evolved those benefits dried up for West Mercia and actively went into reverse.
"This position is supported by evidence from both internal and external financial scrutiny, police performance inspections and feedback from within the police force.
The decision to end the Alliance is no reflection on the work of the officers and staff in either force.
"We fully acknowledge their commitment to keeping communities safe, regardless of force borders, and are grateful for their professionalism serving as part of the Alliance since 2012.
"The central issues with the Alliance lie in how it was set up seven years ago.
"It is no secret that it was born out of an immediate need for both forces to make significant financial savings.
"To that end, it served its short term purpose.
"However, that situation has now shifted.
"We are no longer facing reductions to our service and our police force has modernised significantly.
"Officer numbers have increased in West Mercia by 215 in the last year to ensure our force has the capacity to respond effectively to increases in demand that have been seen by police forces nationwide.
The public in West Mercia need those resources to be fully focused on delivering the best possible services, tailored to their communities.
"However, the terms of the Alliance prohibit our police resources from doing that.
"Having overcome the immediate financial challenges of a few years ago, we have found ourselves stuck in a collaboration where Warwickshire contributes just 31 per cent of resources to the Alliance, but has a 50:50 say on governance, giving them a disproportionate influence on West Mercia’s policing decisions.
"This is not sustainable, and as the larger force, was always going to negatively and disproportionately impact West Mercia.
"This impact is shown clearly in the recent PEEL reports from HMICFRS, where the same services, run by the same people, using the same resources, were judged to be providing a better service to the communities of Warwickshire, than they are in West Mercia.
"That ‘50:50’ governance structure has created situations where one Chief Constable has been able to countermand the operational needs of another and actively prevent them from acting in the best interests of their communities.
"It has created situations where West Mercia has been blocked from achieving major benefits in efficiencies to reinvest in frontline services.
"It has left West Mercia picking up the significant costs associated with hosting 80% of all Alliance functions.
"It has left West Mercia locked into a 69:31 cost-sharing model, which does not accurately reflect the higher level of services that Warwickshire actually consumes.
"The total cost to the public in West Mercia each year is significant, both in terms of finance and operational policing, and yet West Mercia has been effectively powerless to address any of these issues, without the agreement of Warwickshire.
"This is why it was ultimately necessary to end the Alliance.
"Since serving notice of termination we have ensured robust plans are in place to ensure the full, continued delivery of policing services to our communities.
"We are fully confident there will be no risks to public safety in West Mercia as a result of the Alliance ending.
"Simultaneously, we have made numerous offers to Warwickshire for continued collaboration.
"We have offered support on the specific areas where Warwickshire have requested it, on very reasonable terms. These offers have all been rejected by our Warwickshire counterparts.
"As things stand, negotiations between all parties have ended, without agreement.
"We now anticipate intervention from the Home Office in the coming days to allow further time for Warwickshire to transition to a standalone model.
"We would have no choice but to respect any decision made by the Home Secretary.
"We also understand that a high court injunction is being applied for by Warwickshire to try to prevent the termination of the current alliance arrangements.
"While we have been clear throughout that we would take an open, reasoned, pragmatic approach to negotiations, we have been unwilling to accept the wrong deal for our communities and our police force.
While we would always seek to support another police force, we will not allow West Mercia to be held to ransom.
We cannot simply accept the continuation of the current arrangement, which sees West Mercia significantly subsidising a neighbouring force, to the detriment of our police and our communities."