Doctors are worried that religion is being seen as unhelpful
Doctors have voted down a proposal calling for them to be given a right to pray for patients without facing disciplinary action.
The British Medical Association conference in Liverpool debated a motion saying medics should be free to discuss spiritual issues.
But delegates at the union's annual meeting refused to back the proposal.
The government always opposed relaxing the rules, saying spiritual care was for the NHS Chaplaincy Service.
The General Medical Council code suggests that discussing religion can be part of care provided to patients - as long as the individual's wishes are respected.
But at the start of this year the Department of Health issued guidance warning about proselytising.
It said that discussing religion could be interpreted as an attempt to convert which could be construed as a form of harassment.
It comes as NHS trusts have taken a hard-line in a number of recent cases.
Last year community nurse Caroline Petrie was suspended by North Somerset NHS Trust after offering to pray for a patient, although the 45-year-old was later allowed to return to work.
Terry Sanderson, president of the National Secular Society, said: "The BMA conference has been very sensible in refusing give this unfettered permission to religious doctors to offer prayers to patients.
"The restrictions are there for a very important reason - to protect patients from embarrassment, irritation and possible conflict with their doctor."