Prime Minister Boris Johnson was confronted in hospital by the father of a sick child who said the NHS is being 'destroyed'.
Omar Salem, whose furious tirade was captured by TV cameras accompanying Mr Johnson on his tour, told the Prime Minister his daughter 'nearly died yesterday'.
The incident happened at Whipps Cross University Hospital in Leytonstone, East London. Mr Johnson was visiting the maternity ward.
The father - who later confirmed he is a Labour activist - said: "My daughter nearly died yesterday. A&E guys were great, but we then came down to this ward here."
He added that the ward was understaffed. It is not known know what the young girl's condition is.
In a bizarre moment, when the man admonished Mr Johnson for visiting the hospital for a 'press opportunity', the Prime Minister denied there were press present.
Mr Salem pointed to the TV camera which captured the entire incident.
Following the confrontation, Mr Salem confirmed on Twitter that he is a Labour activist campaigning against Brexit. He added: "Boris Johnson had the temerity to come to Whipps Cross Hospital on the children's ward that my seven-day old daughter is on, having been admitted to A&E yesterday gravely ill.
"The A&E team were great but she then went for hours on the ward without seeing a doctor."
A spokesman for the prime minister later said Mr Johnson was visiting public services to see for himself the reality of the situation.
They added the prime minister was "not going to hide away from those circumstances when he goes on these visits, and so obviously is keen to talk to people and empathise and see what he can do to help.
"It's also a reminder of why exactly he is so keen to make the NHS a priority."
Mr Johnson was heckled and confronted several times last week during visits to the north of England.