The move to tighten monitoring of hospital death rates was announced by Baroness Jay, a health minister, in the first official response to the Bristol heart surgery case currently being considered by the General Medical Council.
The announcement surprised officials at the unit that monitors deaths after surgery, who warned that making participation by surgeons mandatory could lead some to lie.
Ron Hoile, of the National Confidential Enquiry into Perioperative Deaths (deaths within 30 days of surgery) said: "The point [of having a voluntary system] is that we hope people will be honest. We are concerned that coercion will produce untruths."
There are about 18,000 deaths a year following operations, of which one in ten is investigated.