Local police powers 'threatened by cuts'
Local services in England and Wales will be most affected by government cuts to the policing budget, according to a think tank report.
The Universities Police Science Institute estimates that the government grant for local policing will fall by £1.36bn over the next four years.
Report author Dr Timothy Brain expresses concern about whether forces could handle future unrest.
The Home Office said the changes imposed will be "manageable".
It said it will stick to its decision to cut police spending in order to reduce the budget deficit.
Dr Brain is the former chief constable of Gloucestershire, and Cardiff's Universities Police Science Institute is based on a partnership between Cardiff University, South Wales Police and the University of Glamorgan.
Dr Brain's study analysed the combined effect of last year's Spending Review, the police settlement grant and spending announcements by all 43 local police authorities.
It comes a week after rioting, looting and arson spread from London to parts of England, prompting a debate about the future ability to mobilise officers to deal with such disorder.
The Police Federation has said that if the riots had happened in a year's time forces would not have been able to deploy resources in the way they did and Labour leader Ed Miliband has urged the government to "think again" about police cuts.
But the prime minister has maintained that the aim was to cut bureaucracy and the visible policing presence would not be reduced.
"We will still be able to surge as many police officers on to the streets," he told MPs during a debate on the riots.
In his report, Dr Brain challenged claims by ministers that the cuts can be largely absorbed by "back office" efficiency savings with little impact on front line services.
He predicts a total of 16,000 front line posts could be lost, which is around the same number of officers called in to deal with the unrest in London last week.
"Ministers expect the brunt of such losses to fall in the so-called back office, but with as many as 16,000 police officer posts going, there is little prospect of the front line being unaffected," he said.
He said the growth in officer numbers since 2004 had been "principally to enable neighbourhood, or community, policing".
Dr Brain, who is an honorary senior research fellow at the Institute, concluded: "It is likely it will be in neighbourhood policing where the greatest impact will be felt. Police services and officers' morale are both likely to suffer."
The Home Office said it was sticking by its decision to reduce police spending in order to reduce the UK's budget deficit.
A spokeswoman said the "urgent need" to take action to address the budget deficit was "clear from events across the world right now".
She said: "The reductions in the police budget for the spending review period are manageable.
"There is no question the police will still have the resources to do their important work."
The spokeswoman added that at the end of the spending review period forces will still have enough officers to deploy in the numbers seen during last week's riots across England.