The NHS in England would see £37bn ($47bn) worth of additional funding over the next five years under a Labour government, Jeremy Corbyn will announce on Monday 15 May. The general election pledge also includes taking millions of patients off waiting lists and fixing "broken" A&Es.
"This is about having a health service for the many. In the past seven years the Tories have driven our National Health Service into crisis," Corbyn will tell the Royal College of Nurses Conference.
"A&E departments are struggling to cope. Waiting lists are soaring and, and as we saw last week, Tory cuts have exposed patient services to cyberattack.
"Imagine what would happen to the NHS if the Conservatives under Theresa May were to have another five years in power.
"It would be unrecognisable: a national health service in name, cut back, broken up and plundered by private corporations."
Labour said the investment boost, which includes £10bn for upgrading NHS England's IT systems, will be paid for by an increase in income tax for the top 5% of earners, a rise in corporation tax, and a higher rate of insurance premium tax on private medical insurance.
"Jeremy Corbyn can't deliver any of this because his nonsensical economic policies would damage our economy and mean less money for the NHS, not more. Just look at Wales where Labour cut funding for the NHS," a Conservative spokesperson said.
"We are putting an extra £10bn into the NHS and with strong and stable leadership from Theresa May we will be able to secure the strong economy our NHS needs."
Labour's pledge comes just days after seven NHS trusts were hit by ransomware cyberattacks on Friday 12 May. IT experts are investigating the origins and full damage from the attack.
The Conservatives attacked Shadow Home Secretary Diane Abbott for being "missing" in the wake of the attack.
"The world is facing an unprecedented global cyberattack and Jeremy Corbyn is clearly too scared to let Diane Abbott talk about it," said security minister Ben Wallace.
"Instead she has become a keyboard warrior criticising our cyber defences as 'snooping' – suggesting she would immediately tie the hands of the men and women who try to keep us safe.
"Her shambolic attempts to explain Labour's police policy were bad enough, but this underlines yet again that she is simply unfit to be Home Secretary and we would all be less safe with her and Jeremy Corbyn in charge."
But questions were also raised about the whereabouts of Health Secretary Jeremy Hunt as Home Secretary Amber Rudd led the government's response to the cyberattack.