Jeremy Corbyn has claimed nine out of 10 NHS trusts are "unsafe" during an attack on the Government's record which prompted his deputy to do a "dab".
The Labour leader said the Conservative administration has put the NHS and social care in a "state of emergency", adding that a government that invests in the health service is needed.
Labour deputy leader Tom Watson then appeared to dab - a gesture which involves raising one arm and hiding your face as if you are about to sneeze.
Prime Minister Theresa May accused Labour of replacing "boom and bust" with "borrow and bankrupt".
Ahead of by-elections on Thursday in Copeland and Stoke-on-Trent Central, Mr Corbyn used Prime Minister's Questions to criticise the Government's approach to the NHS.
The final exchange between the two leaders resulted in noisy and angry scenes in the Commons.
Mr Corbyn said "overstretched" nurses are struggling to provide the quality of care needed for patients at the end of their lives.
He told Mrs May: "The lack of care in the community prevents people the dignity of dying at home.
"There is a nurse shortage - something should be done about it, such as reinstating the nurses' bursary.
"Your Government has put the NHS and social care in a state of emergency. Nine out of 10 NHS trusts are unsafe."
Tory MPs reacted angrily to this claim, with one shouting: "Absolute rubbish."
Mr Corbyn went on: "Eighteen thousand patients a week are waiting on trolleys in hospital corridors."
As Tory MPs continued to shout, Mr Corbyn added: "It seems to me some members don't want to be concerned at the fact that there are 1.2 million elderly people not getting the care they need.
"The legacy of (Mrs May's) Government will be blighting our NHS for decades - fewer hospitals, fewer A&E departments, fewer nurses and fewer people getting the care they need.
"We need a government that puts the NHS first and will invest in our NHS."
Mr Watson then appeared to bring out the dab dance move.
Mrs May said Mr Corbyn should consider correcting the record as 54% of hospital trusts are considered good or outstanding, adding: "Quite different from the figure that he has shown.
"Secondly, I will take no lessons on the NHS from the party - oh, oh, the deputy leader of the Labour Party says we should take lessons from them on the NHS.
"I won't take any lessons from the party that presided over Mid Staffs hospital. And they say we should learn lessons.
"I'll tell you who should learn lessons - it's the Labour Party, who still fails to recognise if you're going to fund the NHS - and we're putting more money in, there are more doctors, more operations, more nurses - you need a strong economy.
"But now we know Labour has a different sort of phrase for their approach to these things.
"Remember Labour used to talk about boom and bust? Now it's no longer boom and bust - it's borrow and bankrupt."
Earlier, Mrs May called on Mr Corbyn to apologise for previously claiming the Government had offered a "sweetheart deal" over social care funding to Tory-led Surrey County Council.
Mrs May said: "Those claims were utterly destroyed the same afternoon. So rather than asking the same question, he should stand up and apologise."
Mr Corbyn replied: "Far from apologising, it's the Prime Minister who ought to be reading her correspondence and answering the letter from 62 council leaders representing social services authorities who want to know if they're going to get the same deal as Surrey, as they are grappling with the crisis which has left over a million people not getting the social care they need."