The Government risks "unravelling" the NHS irreversibly if it fails to re-think key elements of its plans to reform the health service, a doctors' leader has warned.
Dr Clare Gerada, chairman of the Royal College of General Practitioners (RCGP), said there were "several elements" in the Health and Social Care Bill which, if enacted, would "cause harm" to patients and potentially destabilise the NHS forever.
The pause called by the Government in the passage of the Bill should be used for a rewrite of the section dealing with competition, she said.
Dr Gerada told the BBC: "I would hope that during this pause that actually the Government will reflect on what we are all saying and will rewrite the part of the Bill which is actually risking the NHS, and risking the NHS being unravelled irreversibly forever and delivering in the end worse patient care."
Her remarks were made as the RCGP wrote to the Prime Minister outlining "serious concerns" regarding aspects of the proposals and offering a number of recommendations.
The NHS must remain a comprehensive service available to all, free at the point of use and based on clinical need, not the ability to pay, the RCGP has said.
The move comes after Deputy Prime Minister Nick Clegg threatened to veto the reforms unless they were substantially improved.
The RCGP letter details nine recommendations over issues ranging from the need for clarity about the implications of EU competition law to an "absolute" assurance that the Bill would not force doctors to breach their duty of confidentiality. Other recommendations include making sure that providers cannot charge patients for services that are currently free and that consortia remain publicly accountable for all commissioning decisions.
Shadow health secretary John Healey said: "The letter is a red card for David Cameron's NHS plans and reinforces Labour's warnings. From competition law to charging patients, GPs are making it clear they don't want the Tories' free market NHS and the Prime Minister must now make radical changes to his health plans in order to regain the trust of NHS professionals."
Speaking on BBC Breakfast, Dr Gerada said: "We are not against competition, we are not against reform, but what we fear is that, once we move down the road of unfettered competition, we will get many, many alternative providers."