The traffic wardens are already tracked by satellite

Stoke-on-Trent City Council is looking at issuing the mini-transmitters, disguised as name badges to some staff.

Threats and four-letter words against staff are transmitted instantly to a 24-hour monitoring centre and recorded for use in court.

The Identicom, which looks like an ordinary name badge worn round the neck, is already in use within the NHS.

The council confirmed it was evaluating the device with a view to equipping staff who come into regular contact with the public.

Traffic wardens would probably be the first to receive the badges, said a council spokesman.

Panic buttons

"It's widely acknowledged that parking attendants are the council officers most likely to suffer abuse in the course of their job," he said.

"They are the ones who most consistently do get abused, usually verbally, but sometimes physically as well. If we were to adopt this system they would be the most likely people to have it."

Stoke-on-Trent's traffic wardens are already some of the most technologically equipped in Britain.

They carry GPS locators to show their position, and hand-held computer-cameras used to photograph illegally parked vehicles and transmit the pictures back to base.

All wardens also have panic buttons which they can press to raise an alarm. The Identicom also operates as a sophisticated panic button, but includes an internal microphone and mobile phone-style transmitter.

"How it works is you have your ID badge and it's got a button on the back," said the spokesman.

"If you feel you might be going into a hazardous situation, you set it for a period of time, say five or 10 minutes.

"If you then don't press that button again in five or 10 minutes, it automatically triggers an alarm and goes into record mode. You can also have the microphone on all the time.

"We're giving demonstrations of this device to our safety officers in different departments around the council to see what their reaction is and whether it would be a useful thing."