David Cameron and Boris Johnson pulled over their car this morning after noticing a woman who had collapsed on the street in Harrow, according to the London Ambulance Service.
Paramedic Dominic Stark, who attended the scene, said: “I was told the Prime Minister and Boris Johnson had pulled over when they noticed a woman collapsed on the street.
"When I arrived a few minutes later, I found the PM holding the woman’s hand. I took over caring for the patient and they left a few minutes later.”
The patient was later taken to hospital.
It is understood she was spotted by the London mayor who was travelling with the Prime Minister to a campaign event.
The woman was initially cared for by the Mr Cameron's protection officers who are trained in first aid.