Theresa May must take action to "save the NHS from death by a thousand cuts", Jeremy Corbyn has said.
The Labour leader urged her to "face up to the reality" as the NHS dominated the pair's exchanges at Prime Minister's Questions.
Shouts of "resign" aimed at Mrs May could be heard from some Labour backbenchers as she defended the Government's record, telling the Commons: "There is only one part of the NHS that has seen a cut in its funding - it's the NHS in Wales under a Labour government.
"This is a Government that is backing the NHS plan, that is putting more money into the NHS, that is recruiting more doctors and nurses, that is seeing new treatments come on board which ensure people are getting the best treatment they need."
Mr Corbyn had alluded to Foreign Secretary Boris Johnson's suggestion of an extra £5 billion for the NHS.
He said: "It's been reported that a man froze to death waiting 16 hours for an ambulance. Last week a young gentleman called Chris wrote to me saying 'My friend's 93-year-old father waited four hours for an ambulance after a fall'."
Mr Corbyn said these are not isolated cases and are common across the country, adding: "It needs money, it needs support and it needs it now.
"The Prime Minister is, frankly, in denial about the state of the NHS. Even the absent Foreign Secretary recognises it but the Prime Minister isn't listening."
Mr Corbyn said the NHS is being "starved of resources" and people are "dying unnecessarily in the back of ambulances and in hospital corridors".
He went on: "GP numbers are down, nurses are leaving, the NHS is in crisis.
"Tory MPs might not like it, but I ask this question of the Prime Minister - when is she going to face up to the reality and take action to save the NHS from death by a thousand cuts?"