Government and police 'must engage'
It cannot be in the country's best interests for the Government and police to be "distracted over so many issues" of reform, senior officers are to warn.
Derek Barnett, president of the Police Superintendents' Association, will urge Home Secretary Theresa May to "change the narrative from gloom and criticism" and to work with the police.
His warning comes as Mrs May prepares to address superintendents from across England and Wales.
Forces face the most radical reforms to policing in more than 50 years, but Mr Barnett will say the police and Government "have to find ways to work together".
"It cannot be in the interests of the country for the police service and the Government to be distracted over so many issues," he will say. "As a matter of urgency, you should seek to engage meaningfully with the leaders in policing, we await your call. There is so much more that binds us than separates us. Let us not squander this chance to make policing history for the right reasons - together."
Speaking at the association's annual conference near Kenilworth, Warwickshire, he will also urge the police service to come together to "find a common stance on the key issues confronting us".
These include whether there should be a professional body for policing, whether direct entry to officer class should be brought in, and what the future structure of the service should look like.
Government budget cuts are widely expected to lead to the loss of 16,000 officers and a further 18,000 police staff while a wide-ranging review of police pay, conditions and pensions risks damaging morale. There are also plans for directly elected police and crime commissioners to be brought in to replace existing police authorities from next year.
Mr Barnett will tell superintendents from across England and Wales: "For too long it has seemed from the outside that the various levels of the service cannot co-exist. We have allowed ourselves to be seen as reluctant to change.
"We have an amazing record of accepting reform and change over many years, significant changes to terms and conditions and working practices that seldom attract the recognition they deserve. We are proud of our successes but have to learn to be less defensive when faced with justifiable criticism."