Chief constables of two forces want to explore possibility of merger to create force area stretching from Isles of Scilly to Bournemouth

A new police force covering a patch 250 miles wide and with more than 1,000 miles of coast could be created by the merger of two forces.

The chief constables of Devon & Cornwall and Dorset police have written to the government saying they want to explore the possibility of a merger.

They deny that it is simply about saving money but claim a merger could be a way of making a more efficient single force. The forces will consult members of the public, local councils and MPs. The idea is likely to be met with resistance if a merger leads to any cut in the number of officers.

If it does happen it will be one of the biggest shake-ups since 1974, when the existing structure came into being. There are currently 43 police forces in England and Wales.

Shaun Sawyer, the Devon & Cornwall chief, and Debbie Simpson, chief of the Dorset force, made the announcement in Exmouth in Devon.

They said there was already a strategic alliance between the two forces that worked well. Two deputy chief constables work across both forces, and departments such as road policing span both. A number of support services such as administration, IT and human resources are also shared.

In a statement the chiefs said this had led to “significant efficiencies and better working in the last four years” but they added: “One avenue now being explored further is the possibility of a full merger between the two forces uniting Devon & Cornwall police and Dorset police into one police force.”

They added: “Policing has faced some significant funding challenges in recent years and we do not see this landscape changing. To preserve local, neighbourhood policing and deliver safeguarding within our communities, as well as an ability to respond to emergencies and emerging threats as effectively as possible, we view closer working as the only way forward.”

A new force area would stretch from the Isles of Scilly in the far south-west to Bournemouth in the east. Devon and Cornwall is already England’s largest force area.

The chiefs said: “We realise there may be statutory obstacles to overcome and there is a lot of work to be done to understand the benefits and challenges ahead. We will also ensure that the views and feelings of the public are taken account of.

“As a result, a decision is unlikely to be made quickly but we are absolutely committed to exploring the possibility of a merger in order to continue to provide a sustainable police service for all of our communities in the future.”

There have been calls over the years for forces to be merged. Tony Blair’s Labour government wanted to reduce the number of forces to 28 but the policy was scrapped because forces could not agree on how to do it.

In 2013, the eight territorial police forces in Scotland were merged into a single force, named Police Scotland.

Responding to the move from Devon & Cornwall and Dorset, the police minister Nick Hurd said: “While the government does not believe compulsory mergers are the way forward, we will look at proposals from any forces that wish to voluntarily merge with each other.

“We have always made clear that such requests would need to be accompanied by a robust business case and that the government will only support proposals where the case shows a clear benefit to the public and where it has sufficient community consent.”