Tony Blair has admitted his NHS reforms have been "really tough" for staff but said waiting list cuts, new hospitals and more staff were a sign of success.
Mr Blair hailed "progress" in NHS over the past decade
He said he did not think there would be a reversal of the "essential course" of more choice for patients and greater competition between health providers.
And he said he expected NHS staff to make a "more rational assessment at the conclusion" of the reform process.
Both the Lib Dems and the Tories say the 10 years have been wasted.
He was addressing a medical audience two days after junior doctors called for Health Secretary Patricia Hewitt to resign.
On Saturday, the British Medical Association's junior doctors conference called the online Medical Training Application Service for doctors' jobs "shambolic".
Health workers are also threatening to strike over a decision to stagger a 2.5% pay rise.
Mr Blair was asked how he would "restore trust" among NHS staff.
"Whilst the change is going through it is extremely difficult," he said, using the academy schools and university financing as examples of other reforms where "disaster" had been predicted.
"How you do it in a system that is as big and complex as the NHS is really, really tough. But I honestly don't belive that you are going to get a reversal of the framework."
He added: "How do you then get people through it? You get them there and then people will make a more rational assessment at the conclusion of it. "
"I've been through this so many times, I just think its really tough while it's happening. What we've just got to do in a sense is hold our nerve," he said, while acknowledging that debate was necessary.
He also said that "patients will take these reforms as being right" and that their experiences of the NHS were "immensely more positive" than a decade ago.
The prime minister said cardiac care, cancer treatment, emergency services and mental health services had all improved during the past decade.
Mr Blair, who warned voters in 1997 they had "24 hours to save the NHS", used the event organised by the King's Fund think tank to set out why he feels he has been successful.
"I personally think that the concept of a less, or non, monolithic system of healthcare, greater competition, greater patient choice, I believe those reforms and that framework will stay in place.
"I can't see any government turning their back on that."
He added: "That said, there are real challenges that remain. I think there are things we have got wrong as well as got right.
"In respect of the reforms, it's true to say that in the first two or three years we didn't push forward fast enough some of the reform agenda."
But the Conservatives say, during Labour's time in power, the NHS has gone on a "circular and wasteful journey" back towards policies of the last Tory government.
They are publishing a report claiming there have been failures on issues like mixed-sex wards, hospital acquired infections and dentistry - as well as financial deficits.
Lib Dem leader Sir Menzies Campbell says Labour's legacy will be one of "war and waste" - as he launches his own report into what he calls the greatest failings of the New Labour decade.
He says, despite a promising start, that the government has been "deeply damaging" to Britain's interests.
This week marks the 10th anniversary of Labour's return to power, and will also see the local elections across England, as well at the Scottish Parliament and Welsh Assembly.