Trust between doctors and patients risks being shattered by new government proposals, the British Medical Association will warn today.

At a time when the medical profession feels it is facing a "crisis" in the NHS, the BMA's annual gathering starting today promises to be a forum for angry and contentious debate.

Opening the Annual Representative Meeting in Cardiff, the association's chairman, Dr Hamish Meldrum, will speak of the threat to the bond of faith between doctors and patients as an Ipsos MORI poll shows they are the most trusted profession, with an 88 per cent rating.

Government ministers and politicians are at the bottom of the poll, with 17 per cent and 14 per cent believing they will tell the truth. "In times of crisis, trust is more important than ever. This trust will be key to getting through the challenges we face over the next few years. And yet there is a danger that this trust could be put at risk by some of the Government's plans," said Dr Meldrum.

He added that the public will not let the Government gamble with the NHS and that doctors are not prepared to see this trust abused by policies that could undermine doctor-patient relationships.

The Coalition has already endorsed wholesale changes to controversial health reforms – giving patients a right to challenge poor services for the first time – after recommendations put forward by the NHS Future Forum. However, there remain serious concerns about the Health and Social Care Bill.

Today the editors of the British Medical Journal (BMJ) said: "It would be better for the NHS, the Government, and the people of England to sweep [the amended Health and Social Care Bill's] mangled remains into an unmarked grave and move on."

In an editorial published today, Dr Tony Delamothe and Dr Fiona Godlee, said they were concerned the Future Forum recommendations would leave "the NHS with a similar proportion of bureaucrats to the Austro-Hungarian empire on the eve of the First World War – and about as flat footed".

The BMA is concerned about proposals to offer performance-related bonuses to GPs' consortia if they do well financially. Dr Meldrum said that if patients even suspected that their doctors would be rewarded for how well they do financially, it would be a serious breach of trust.

He added: "The more difficult the decisions we face the more trust is required – trust among all those with a stake in the outcome. And we are facing some very difficult decisions."

Patients and the public must be an integral part of the decision-making process, said Dr Meldrum, adding that the challenges now facing the NHS were the greatest in its history, particularly in terms of financial challenges.

A Department of Health spokesman said: “On the contrary, we believe our plans will improve trust as doctors will be free to tailor services around their patients. We are also ensuring local clinicians, including GPs, are fully accountable for improving the quality of care for patients in their communities.

“GPs already take decisions about when to refer patients, when to prescribe medicines and what treatments they should be given, and the first duty of doctors will always be to their patients. “