Ed Miliband says NHS to be 'defining issue' at next election
Labour are pledging to make the NHS the "defining issue" at the next election if the government does not drop its plans to overhaul the service.
David Cameron is insisting he will press ahead with reforms to the NHS in England, despite widespread criticism.
Under the proposals, family doctors will have more control over their budgets and there will be a greater role for the private sector.
Labour's Ed Miliband has accused the prime minister of "broken promises".
During a visit to the Royal Bolton Hospital, the Labour leader said Mr Cameron had made "solemn promises" at the last election: "No going back to waiting for hours on end in A&E. Three thousand more midwives. An end to hospital closures. And no more top-down reorganisations."
Mr Miliband accused Mr Cameron of breaking "all these promises and more... it is bad for our NHS and bad for politics".
He said: "Before he became prime minister, David Cameron concealed his plans for creeping privatisation of our National Health Service.
"So people didn't get a vote on these plans at the last election. But I give you my word that if he goes ahead, they will be a defining issue at the next."
The next general election is scheduled to be held in spring 2015.
The main unions and professional bodies representing doctors, nurses and health service staff are now opposed to the proposed changes.
Mr Miliband called at Prime Minister's Questions last week for the bill to be dropped, and is urging the Mr Cameron to "listen to doctors and nurses and the 140,000 who have signed the petition urging him to drop the Bill".
Earlier this week Downing Street insisted ministers were fully behind the reforms and rejected suggestions that Health Secretary Andrew Lansley should be sacked.
Mr Cameron said on Sunday he strongly supported the founding principles of the NHS, including "health care for all, free at the point of use, unrelated to the ability to pay".
But he added: "While the values are right, the system isn't. It needs to change - and that is why I am at one with Andrew Lansley, the reform programme and the legislation going through Parliament."
Following Mr Miliband's comments, health minister Simon Burns said: "Ed Miliband can talk the NHS down all he likes, but the truth is that services are getting better all the time - with shorter waits since the election, 820,000 more people able to access an NHS dentist, 15,000 fewer administrators, 4,000 more doctors and 600 more midwives.
"Our plans deliver control for patients, power for doctors and nurses, and less bureaucracy. Labour still have no plan to help our NHS meet the challenges of the future. Their approach is simply one of cynical opportunism."