A new campaign to help people communicate their imminent danger to police has been launched by the Independent Office for Police Conduct.

The 'Mark Yourself Heard' scheme is raising awareness about the Silent Solution System for people in an emergency who can’t speak.

If no particular emergency service is requested after calling 999 BT operators will divert the call to a police handler.

If you are calling from a mobile, the Bromley Neighbourhood Watch Association recounted the following advice.

"Speak to the operator if you can, even by whispering. You may also be asked to cough or tap keys on your phone in response to questions. If making a sound would put you or someone else in danger, and the BT operator cannot decide whether an emergency service is needed, your call will be transferred to the Silent Solution system.

"This is a police system used to filter out accidental or hoax 999 calls. It also exists to help people who are unable to speak but who genuinely need police assistance. You will hear an automated police message which lasts for 20 seconds and begins with ‘you are through to the police’. It will ask you to press 55 to be put through to police call management.

"The BT operator will remain on the line. If you press 55, they will be notified and transfer the call to the police. If you don’t press 55, the call will be terminated. Pressing 55 does not allow police to track your location on a mobile.

"When transferred to your local police, the call handler will attempt to communicate with you by asking simple yes or no questions. If you are not able to speak, listen carefully to the questions and instructions from the call handler so they can assess your call and arrange help if needed."

The Bromley Neighbourhood Watch Team also explained what would happen if the emergency call was made from a landline.

"Because it’s less likely 999 calls are made by accident from landlines, the Silent Solution system is not used. If, when an emergency call on a landline is received there is no request for an emergency, the caller does not answer questions or only background noise can be heard (and BT operators cannot decide whether an emergency service is needed), you will be connected to a police call handler as doubt exists.

"If you replace the handset, the landline may remain connected for 45 seconds in case you pick it up again. If you pick up again during this 45 seconds and the BT operator is concerned for your safety, the call will be connected to the police. When 999 calls are made from landlines, information about where you’re calling from should be automatically available to call handlers to help provide a response."