
if you remember the series Yes (Prime) Minister, there are about four episodes in which Sir Humphrey explains very clearly to the Minister that the Minister is responsible for **ck-ups in his department (not in such terms, of course). So ... start fining Ministers, not departments, and make it personal. Also given the amount of public trust implicitly placed in public servants such as Ministers, add a 10x multiple on the fine. Oh, and MPs on select committees are responsible for supervising Ministers, so lthey should share the pain.
After all, there can;'t be a single MP out there who wouldn't vote for such a proposal, because they're all "cleaner than clean" and would have nothing to worry about - so if they do vote against it, Inspector Knacker can start asking them why.
PS My personal favourite Yes (Prime) Minister is the one where Hacker suggests civil servants, given their job security and bullet-proof pensions etc, should be paid as if they were directors of Charities, not compared with commercial/enterprise salaries unless they are taking same risks ("in undustry, if you make a mistake, you get the boot; in the civil service, if you make a mistake, <i>I</i> get the boot")