Officers should wear uniforms on their way to and from work to increase police visibility and help reassure the public, a think tank has suggested.

The right-leaning Policy Exchange said in London that would equate to having an extra 1,200 officers on the streets.

But the Police Federation said the idea was impractical and would make officers and their families potential targets.

The think tank also said millions of pounds would be saved if civilian staff did more jobs performed by officers.

Its report Cost of the Cops said improving the visibility and availability of officers to the public must be a "key strategic priority".

Those heading to work - particularly on trains and buses - should be expected to wear uniforms, it said.

'Hidden away'

It said forces should also consider single patrols, rather than having officers in pairs, to widen visibility further.

The report said police forces in England and Wales wasted almost £150m a year because one in 20 officers carried out roles that could be performed by civilians.

Cuts to police budgets Home Office must cut 6% year-on-year

Equals 20% fall in central government police grant over four years

Effect will not be uniform across England and Wales

Some forces receive more funding through Council Tax than others

So some forces could cut only 14% over period.

Chiefs have a free hand to allocate resources

Proposed new Policing and Crime Commissioners would set priorities

"Too many sworn officers are hidden away in back offices," said Blair Gibbs, Policy Exchange's head of crime and justice.

"Some forces like Surrey and Suffolk became more efficient by hiring cheaper civilian staff but many did not.

"As a result taxpayers have spent at least £500m since 2006 in extra employment costs for over 7,000 police officers who have a uniform, but who aren't policing.

"There remains a clear gap between additional police resources and the service delivered. As far as the public are concerned, the unprecedented expansion in officer numbers since 2001 may as well never have happened."

He said there was "real scope" for the police to become more efficient and effective despite the challenging budget cuts ahead.

BBC home affairs correspondent Danny Shaw said the detailed report provided backing for the government's case that forces can make cuts without affecting front-line policing.

It also found:

Since 2000, funding for the police in England and Wales had risen by 25% in real terms

In 2010, households paid £614 per year for policing, up from £395 in 2001

UK policing cost "significantly" more than other developed countries such as the US, Australia, Canada and New Zealand

Police visibility had remained low and there had not been a "step-change" in performance on crime

Significant numbers of sworn officers made no arrests at all last year - as high as half of all officers in some forces

Greater Manchester Police Chief Constable Peter Fahy, who speaks for the Association of Chief Police Officers (Acpo), said many office-based jobs required trained officers.

He said: "It is crucially important the police officers are used in roles which require their expertise, powers and experience.

"That said, this doesn't just apply to the front line, there are many office-based jobs where police officers are required, including handling intelligence, delivering training, or processing offenders through the criminal justice system."

Officer obligations

In times of emergency like the recent disorder, all officers can be deployed for operational duties, he added.

And Mr Fahy told the Today programme that the idea of officers wearing their uniforms on the way to work was "a bit of a red herring".

He added: "Most officers travel to work now in cars, I'm not sure how many of the public would see it. If you're an officer and you're trying to deal with an incident, even on a bus or a tube [when] you're on your way to work and you don't have your radio and protective equipment, then that is an issue.

"Our officers already make huge numbers of off-duty arrests. There is an obligation on every police officer, on duty or off duty, to intervene if they see something."

The Police Federation, which represents rank-and-file officers in England and Wales, said the think tank's claims did not translate into reality.

Chairman Paul McKeever said the suggestion that officers should wear uniforms to work took no account of the risks - including the threat of reprisals - as they emerged from their homes.