In addition, when the lines are very busy, call handlers are instructed not to give out vital medical instructions to patients suspected of having a heart attack.
Normally, they would issue what is known as 'interim care advice' to patients while they wait for an ambulance, but during the busy periods – sometimes up to twice a week – they are banned from giving out the advice so they can hang up ready for the next call.
Patients dial 999 as normal and if their condition is classified as not being an emergency, they get transferred to a hub of paramedics and nurses at the call centre.
They include: Just last week the NHS said heart attack and stroke victims will have to wait longer for an ambulance under controversial new targets.
Patients calling 999 are being refused ambulances and told to make their own way to A&E.