Consideration should be given to scrapping NHS Direct as part of a scaling back of health spending, GPs say at their annual conference.
The British Medical Association questioned the effectiveness of the telephone service, claiming it delayed patients getting healthcare.
They also highlighted spending on new buildings and management as areas for potential savings.
But GPs also said possible cuts to community services were a concern.
The NHS has been told to find up to £20bn of savings by 2014 even though the health service is due to see rises in its budget in the coming years.
This is because of the increasing demands from an ageing population, new drugs and lifestyle changes such as obesity.
Doctors at the annual conference in London acknowledged savings were inevitable, but urged ministers to target them at the most wasteful areas of the NHS.
Dr Laurence Buckman, chairman of the BMA's GPs committee, highlighted the telephone service - rather than the website - provided by NHS Direct.
He described it as an "interposition" between the patient and clinical care.
"It is an interposition between the patient and healthcare. It stops them getting through to nurses and has ended up an expensive telephone service."
Dr Buckman said if it was to go patients could contact their out-of-hours GP service instead, although he acknowledged in some areas this would need improving.
He also said there were "unnecessary" tiers of management which could go, while new hospital building schemes funded by private money through PFI, walk-in centres and polyclinics should be stopped.
He was supported by fellow GPs at the conference.
Dr Nigel Watson, a family doctor from Dorset, said it was right to look at NHS Direct alongside these other areas.
"The NHS needs to reduce costs."
But Dr Ivan Camphor, from Merseyside, suggested other essential services were in the firing line instead.
He warned obesity management, palliative care, physiotherapists, district nursing and health visitors could be hit in coming years.
"We plead. We beg. Please don't destabilise the services provided by general practice in partnership with others."
NHS Direct chief executive Nick Chapman said: "The comments made about the propensity of NHS Direct to refer patients on, are not backed up by the data on what we actually do.
"Over half of patients who contact NHS Direct are given self-care advice for their problem, which means they can care for themselves at home without needing to seek face to face appointments."
A Department of Health spokesman said: "All NHS services, including NHS Direct, are regularly reviewed to ensure they continue to meet the needs of patients and offer the best value for money."