Leigh Pateman was serving a sentence for grievous bodily harm when Ellen Marshall died from her injuries last year.
The PM is to give a major speech on Thursday, following a backlash to the Budget, plummeting poll ratings and the first resignation from his Cabinet.
The estimate by actuaries from PwC was made following an announcement about a change to the personal injury discount rate.
TV presenter Gregg Wallace has apologised for claiming complaints about his behaviour came from “a handful of middle-class women of a certain age”, adding he will now “take some time out”.