Labour leader Ed Miliband has pressed David Cameron to drop the proposed reforms of the NHS, branding them a "disaster".
"Every time [Cameron] talks about the NHS he shows how out of touch he is on the ground." Miliband said during Prime Minister's Questions.
He went on to lead a chant of Labour MPs listing the groups opposed to the bill, including 98 percent of GPs, the Royal College of Nurses and the British Medical Association.
"He knows in his heart that this bill is a disaster," Miliband continued. "Will he now drop this unwanted bill?"
Cameron refused to budge and used Tony Blair's own words about reform as a weapon.
"Can I tell [Miliband] something Tony Blair once wrote about the process of reform? He said that it's an important lesson in the progress of reform that change is proposed and often opposed as a disaster," Cameron said.
"[Reform] comes about and within a short amount of time it is as if it has always been so. If you think a change is right, go with it. The opposition is inevitable, but it's rarely unbeatable."
The Health and Social Care Bill has come under renewed fire following editorials in the British Medical Journal, the Health Service Journal and the Nursing Times claiming that further reorganisation of the NHS would be needed in just five years if the bill were passed.
The editorials claimed the bill would leave "an unstable system that is only partially fit for purpose".
The bill proposes extensive reforms, including transferring responsibility for the commissioning of health services to GPs - a move roundly criticised by practitioners.
About 100 amendments are expected to ensure that health secretary Andrew Lansley maintains the NHS as a public service and temper fears about an increased role for the private sector.
While Lansley acknowledged the scale of opposition, he claimed the bill would cut bureaucracy, improve the service and save public money in the long run.
Former health minister Lord Warner told the BBC: "The government will get the bill at the end of the day but at a price".