Police leadership in England and Wales is plagued by “nepotism and bias” and too many chiefs have lost focus on fighting crime, a government-backed report has found.

The inquiry, co-chaired by former home secretary David Blunkett, found a reset was needed at all levels, with scores of top officers facing misconduct inquiries.

The report, released on Monday, covers the 43 forces in England and Wales and finds a “postcode lottery” in how well the public is served.

The report said: “We have also identified systemic causes for concern about the consistency, capability and culture of leadership across the service.

“Put simply, leadership in policing is not consistently of a high enough standard to provide confidence and trust in the attainment of the service which the public deserves.”

Blunkett told the Guardian the police service was not good enough and some of the findings were “staggeringly” poor.

The report finds leaders “insufficiently focused on delivering outcomes for the public”, as in the core goal of cutting crime.

Blunkett said: “Two contradictory things can be true at the same time. You can have outstanding leadership and you can have deep-seated and extremely worrying behaviour.”

Nick Herbert, chair of the College of Policing and co-chair of the inquiry, told the Guardian: “Some forces are very good but some have lost focus on cutting crime.”

The report said a series of scandals involving police chiefs show the need for reform. One is the former Northamptonshire chief constable Nick Adderley who was dismissed after being found to have lied on his CV, and has been charged with fraud and misconduct in public office.

The report said there had been 78 investigations into police leaders since 2018, from the rank of assistant chief constable upwards: “The Independent Office for Police Conduct tells us that common themes in their investigations involve cronyism, nepotism, abuse of position for a sexual purpose and corruption.

“Eight chief constables or former chief constables are either currently under investigation or are awaiting disciplinary proceedings.”

The report finds regular frontline officers know they are badly led, with “just 13% of the constables and 17% of the sergeants” agreeing they worked in a “well led and managed organisation”.

Nepotism in promotions was a key theme running through the findings: “Talent identification and promotions decisions in policing are often shaped in the image of the leaders who are responsible for them at a local level.

“This has created fertile ground for nepotism and bias to influence progression and development.”

One officer told the report: “It is very clearly nepotistic. Jobs for the boys or the girls who’re mates with the right people.”

The report adds: “Professional culture was felt to be broken in specific, systemic ways … the gap between stated values and lived experience is described consistently, manifesting as nepotism, blame cultures, command and-control behaviours, and reluctance to challenge inappropriate conduct.”

Among 27 recommendations are a new national academy of police leadership, a fast stream for future leaders and more money for leadership training, with a current spend of about £4m in a service costing £19bn a year.