The NHS faces a "full blown crisis" unless there is a major change in the way the service is run, Andy Burnham has warned.
The shadow health secretary, who called for social care to be brought into the NHS, said Labour would do "whatever it takes" to protect the health service.
But he warned that a "toxic mix of cuts and privatisation" put the future of the NHS at risk under the current Government's plans.
On BBC1's Andrew Marr Show Mr Burnham said: "I think the NHS in the next Parliament now is looking at a very serious crisis if things stay as they are.
"If we stay with the funding position that the Government has set out, and all the experts say that won't be enough, but also this big reorganisation that they have brought forward, I believe, has put the NHS on the wrong path and that's a path towards increasing privatisation."
He added: " If things stay as they are, if we stick on the plans the Government has set out, the NHS will tip into a full blown crisis in the next Parliament. I think it will be subsumed by a toxic mix of cuts and privatisation.
"Labour is saying we will put additional money into the NHS come what may. We will put more money into the NHS because we need to help it rebuild into a 21st century service."
Mr Burnham said the Government had allowed the market to "run riot" through the NHS and repeated his promise to repeal the law which implemented Andrew Lansley's controversial reforms.
But he accepted the private sector would continue to play a role in providing treatment under a future Labour administration.
"I believe in the public NHS and what it represents. In the end what's precious about the NHS is it puts people before profits. We did bring in private sector capacity to bring down waiting lists to the lowest ever level, but it was different - we were using the private sector in a supporting capacity," he said.
"This Government wants the private sector to be allowed free rein and to be allowed to come in and replace public NHS services and that is allowing the market to run riot through the NHS and that is why we are absolutely committed to repealing the Government's Health and Social Care Act."
Asked about the hundreds of thousands of procedures carried out by private providers in the NHS each year, Mr Burnham said: "W e are saying that the public NHS needs to be pre-eminent.
"So we would have a policy of NHS preferred provider. It has always been the case that the NHS has used extra capacity to bring waiting lists down and we would keep waiting lists down. But I'm not making commitments today about how many will be done in this sector and how many will be done in that.
"But I am saying to you that I would have the public NHS prioritised in that system and I would remove the market. I am very clear that the market is not the answer to 21st century health and care."
Labour has promised to set a seven-day target for patients with suspected cancer to be tested and receive results by 2020, paid for using a levy on tobacco firms.
The money is part of a £2.5 billion annual funding boost for the NHS promised by Labour, although Mr Burnham said the party was not claiming the extra money " solves everything" and there was still "huge" pressure on NHS and social care.
Explaining his plan to integrate health and social care, Mr Burnham hinted he would like to go further and make social care available on the same universal basis as the NHS.
He said: "If we bring social care in, we can actually make the finances stack up because social care is prevention. If you look after people properly in their own homes, if you get rid of the useless 15-minute visits, if you look after the staff properly who care for people, then you can avoid huge expenditure on hospital admissions.
"The NHS can't do that today because it is still set up as a treatment service. So we need to make this big shift.
"You could go further and pay for social care on NHS terms."
He added: "I personally believe, in the long run, if the country agrees, it would be right to provide all care for people on the same basis."
Making social care free at the point of need to all in the same way as NHS treatment is would require extra funding - potentially through increased taxes.
Mr Burnham said: "It would require a big debate in the country. But the Barker Commission recently endorsed this idea that we should pay for care of older people in the same way - that everyone contributes but then everybody is covered for all their care needs.
"We need to see if the country has got an appetite to do that."
The Barker Commission, established by the King's Fund think tank, recommended the rich and middle-aged should be taxed more to pay for NHS and social care.
It recommended that the elderly should be stripped of their free television licences and the winter fuel payment for older people should only be given to those most in need, to help finance the plan.
The Commission, led by Dame Kate Barker, said people with social care needs deemed to be critical should have free care and as the economy improves it should be extended to include people whose needs are substantial.
When someone reaches the age of 40 their National Insurance contributions should increase by one percentage point to contribute towards health and social care funding, the Commission said.
And people who earn more should also be forced to pay increased contributions, they said.
Labour's seven-day test results guarantee in England could result in 40,000 more cancers being diagnosed at an early stage by 2025 and potentially save more than £200 million a year, the party said.
Mr Burnham said: "I've seen the devastating effects of breast cancer in my own family and what that has told me is that you know the earlier people know, the better equipped they are in that fight against cancer.
"I mean that's absolutely the case. But you know sadly here, we only diagnose around half of cancers in the early stage; and one in four cancers are actually diagnosed in A&E and I think that tells you that we're not doing well enough in terms of diagnosing cancer.
"So what we're saying is with these plans, we think around 40,000 cancers could be diagnosed in their earliest stages and that would obviously dramatically affect people's chances of survival."