David Cameron today promised the NHS would remain free to everyone under a Tory government.
The new Conservative leader said he would never go down the route of a health service based on medical insurance.
But he said he wanted to transform the NHS into a more efficient, effective and patient-centred service.
Speaking at the Kings Fund health group in London Mr Cameron said: "Under a Conservative government, the NHS will remain free at the point of need and available to everyone, regardless of how much money they have in the bank."
Mr Cameron said Labour and the Tories were united in the belief that the NHS should be a truly national service, "not just a safety net for the poor while the rest go private".
But he said there were real points of difference between the two parties.
"In every area where Labour are moving in our direction we think they could and should go further," he said.
The Government had not gone far enough in giving a wide range of health providers the right to supply services to the NHS, he said.
Foundation hospitals were not truly autonomous and GPs were still not in the driving seat, the Tory leader said.
His approach to the NHS was based on trusting health professionals and sharing responsibility, he went on.
A Conservative government would give more powers to GPs and create "genuine" foundation hospitals, Mr Cameron said.
The Government had neglected public health - which was to prevent people becoming ill in the first place rather than just treating them when they did, he said.
"We will support the Government where it does the right thing.
"And we will offer constructive criticism when it doesn't."
But he promised the Tories would change course on the NHS.
"No one should be in any doubt: our priorities and attitudes are changing," he said.
"We're proud of the NHS and we're optimistic about its future. Instead of helping a few to leave the NHS and go private, we want the private sector to come and help improve the NHS for everyone."
That was confirmation that the Conservatives are making a major u-turn on their flagship health policy. They are to scrap "patients' passports", which would have offered state-funded subsidies to patients who go private.
Mr Cameron said: "The fact that we have in this country a health service that takes care of everyone, whatever their needs, whatever their background, whatever their circumstances, is one of the greatest gifts we enjoy as British citizens.
"We should never forget it, and never take it for granted."
There must no longer be a question mark over the Tories' commitment to the NHS, he added.
"I want us to leave no one in any doubt whatsoever about how we feel about the NHS today," he said.
"We believe in it. We want to improve it. We want to improve it for everyone in this country."Reuse content