Moves to prevent scandals such as the killer GP Harold Shipman and the appalling standards of care at Stafford hospital have become bogged down in arguments over how the shake-up is funded.

Local authorities and funeral directors have refused to collect what they call a "tombstone tax" or "tax on death" for bereaved families, while Labour has accused ministers of putting the issue on the back burner.

A new charge had been proposed to pay for new independent medical examiners, mooted at around £130, which would be levied on bereaved families of the more than 100,000 people who choose burial each year, while for those whose relatives choose cremation, it will replace the "ash-cash" fees paid to medics for checking bodies before disposal.

The aim is to reduce the thousands of mistakes by doctors each year and alert authorities both to criminal intent and, more commonly, substandard treatment and care. A pilot scheme in Sheffield found death certificates might be inaccurate in one in four cases, while a study by the Office for National Statistics suggested the figure was one in five. The report of the Francis inquiry into what went wrong at Stafford in February was only the latest demand for a new system.