Thousands of officers were drafted in to police G20
"There's extreme frustration that there seems to be trial by media going on," says Paul McKeever, chairman of the Police Federation of England and Wales.
The policing of the G20 protests in London earlier this month has dominated the headlines over the past couple of weeks, with accusations of officers being heavy-handed towards protesters.
More than 180 complaints stemming from the protests have been received by the Independent Police Complaints Commission.
It has launched three investigations into allegations of assault, including one minutes before the death of newspaper seller Ian Tomlinson.
The Police Federation, which represents officers, says it has received numerous e-mails from concerned officers.
Mr McKeever, a serving Metropolitan Police sergeant, told the BBC: "There's a great deal of frustration amongst rank-and-file officers about comments made by politicians and people who really don't have any understanding of policing.
"They're putting two and two together and making five, six and seven. No-one knows what happened and there's an investigation taking place."
Another Metropolitan Police officer who contacted the BBC said: "We really are damned if we do and damned if we don't.
"People's memories are very short and I am in no doubt that if we had a repeat of the chaos of the May Day riots of a few years ago, then the police would have been slammed by the media for not doing anything to stop it."
One of the claims about policing of the G20 demonstrations is that officers removed their numbers from their shoulders to stop them from being identified.
But this is not true, Mr McKeever says.
Officers had been told to wear their fluorescent jackets so they were easily identifiable in the crowds and these did not have numbers on, he told the BBC.
He said an incident when an inspector "refused" to give his number was because they did not have numbers but pips.
And balaclavas had been worn to protect officers from petrol bombs, not to hide their faces, he added.
Officers are trained to follow an "escalation tree" when dealing with protesters - at first they get a verbal warning, which builds up to officers reacting physically with equipment, such as batons, if they continue their behaviour.
"Police officers, when they come on duty, want it to be a quiet demonstration. They respond to what is put before them," Mr McKeever said.
'Fear for life'
"If you look at the early stages of the G20 protests, they're wearing normal police uniform. It's only when they move to the public order stage they wear protective gear.
"The police have tactics which have worked for many years. When policing demonstrations we'll always try to use the lowest number of officers available and as low level as possible. Allow people to go out and exercise their democratic right in a peaceful way."
Tim, an inspector in a southern constabulary, said people forgot that police could also be under attack during demonstrations.
"When you're in that situation, your adrenalin is high and you're outnumbered and encircled by a baying crowd, there are times when you do fear for your life," he said.
The contact Ian Tomlinson had with officers is being investigated
"There are times when you're thinking you need a way out of this, it just needs one more thing to happen and you're in real trouble. Sometimes you need to act to stop it from escalating."
He said the feeling being asked by officers was: "What do the public want us to do?
"Do they want it to be like Thailand where protesters can close down a summit, stop democracy from working? Or [do they want us to] defend free speech and when the situation demands it, step in?"
He echoed the comments of Sir Ken Jones, president of the Association of Chief Police Officers, who said earlier that he did not know of any country other than the UK which did not use water cannon, CS gas or rubber bullets to police protests.
"Other countries pre-empt problems using water cannon and CS gas. If that's what people want us to use, than that should be considered - it potentially could cause less problems for police but is indiscriminate as to who it affects."
The coverage of the G20 policing has had two main impacts - on the morale of officers and public perception, officers argue.
The UK does not have designated riot police - they are officers who have taken on the role in other sections.
"Put yourself in their shoes - officers who work in public order units are volunteers. Would you put yourself forward to do that in future?" Mr McKeever said.
This was echoed by another serving Met officer, Steve.
He said if he were on the list of trained officers or on the Territorial Support Group, he would remove himself immediately - because of what he perceived as a lack of support for officers involved in G20 protests controversy.
Tim said officers on the street are already experiencing fall-out from media coverage.
"It does affect people's view of us, it is pervading across the UK. Everyone is tarred with the same brush but 99.9% of officers do a decent job.
"We're hearing now already comments like 'are you going to kill us, like in London?'," he said.