Keir Starmer has said a Labour government would bring back Tony Blair-style NHS targets to cut waiting times for patients.
The opposition leader accused the Tories of presiding over a "broken" system and said his team would be focused on tackling long waits.
He said that successive Conservative governments had overseen a "cycle of decline" that poses an existential threat to the health service.
And Mr Starmer indicated he would follow a target-driven system like the model pursued by former prime minister Sir Tony Blair.
"The last Labour government did obviously put targets around it so there is a model there that we know can work," he told the i.
"They drove the waiting lists down dramatically over two or three years. It will fall to us to do the same thing."
Speaking to the Telegraph, he revealed Labour would back single-sex hospital wards and accused Prime Minister Rishi Sunak of "sitting on his hands" over a long-running pay dispute as further health strikes loom.
"For me, patient security, safety and peace of mind comes first. That's why we support single-sex wards," he said.
"I think the NHS is broken," he added.
"If they carry on like this, it can't survive - the biggest risk to the NHS is another Tory government."
Last night Labour said patients had been left waiting as long as an hour and 37 minutes for 999 call handlers to pick up the phone.
Freedom of information responses from NHS ambulance trusts in England also revealed that patients were waited up to 3 hours for their 111 calls to be answered in December.
Shadow Health Secretary Wes Streeting said: “After 13 years of Conservative mismanagement of the NHS, patients can no longer be sure their 999 call will be answered or that an ambulance will arrive when they need one. People are just praying they don’t fall ill or suffer an accident.
“Labour will launch the biggest expansion of NHS staff training in history, paid for by abolishing non-doms, so that the NHS is there for us when we need it once again.”
It comes as the Royal College of Nursing (RCN) plans to stage the most extreme strikes in its history, which would see staff walk out with no derogations.
Mr Sunak admitted on Monday that meeting his promise to cut NHS waiting times will be "more challenging" as a result of further industrial action.
The Prime Minister made the pledge as one of his five priorities at the start of the year, but the latest figures showed a record 7.22 million people were waiting to start routine hospital treatment at the end of February.
The RCN is set to return to the picket line after rejecting a pay offer while the British Medical Association's junior doctors also remain locked in a row with the Government over wages.
Mr Sunak claimed he was "still hopeful" that waiting lists could be driven down but described the union's ballot result as "disappointing".
