The "duty of candour" recommended in the Francis report would represent "the biggest advance in patient safety and patients' rights in the history of the National Health Service", campaigners said.
A legal obligation for medical staff to own up to mistakes and be open with families of patients should be implemented by the Government as part of a "new dawn" of transparency and openness in the public health body, the Action Against Medical Accidents (AvMA) said.
The report into standards by Robert Francis QC, sparked by failures at the Mid Staffordshire NHS Foundation Trust, contains a raft of measures to guarantee openness, transparency and learning, AvMA chief executive Peter Walsh said.
"The Government must now accept the recommendation for a legal duty of candour which would represent the biggest advance in patient safety and patients' rights in the history of the NHS," he said.
"So far they have fiercely resisted this. The duty of candour, together with other recommendations to ensure full openness and transparency represent a new dawn for the NHS.
"Organisations that sweep errors under the carpet do not learn lessons. An open and transparent NHS will be a safer NHS."
Emma Jones, from law firm Leigh Day, who claims to represent 120 people and their families who suffered at Stafford General Hospital, said politicians and NHS management must make changes to make sure patients are put first.
"The patient must be the first priority in all that the NHS does," she said. "Patients must receive effective services from caring, compassionate and committed staff working in a common culture, and must be protected from avoidable harm and any deprivation of their basic human rights.
"The measures laid out by Robert Francis of zero tolerance, closing hospitals where there are poor standards of care and a greater focus on compassion in nursing are hopefully measures which the Government will now implement before anything like this can happen again.
"It must take place quickly to prevent the abuse, which we as lawyers are still witnessing. The NHS needs urgent reform to regain its position as a healthcare system which we can all be proud of."