Thanks...but back at the coal face - you can't write per-spec. software when the customer is refusing to tell you the spec's. And (beyond CYA basics) there is no "re-arrange the paperwork on Project Titanic" way around that.

The fix for this situation, more-or-less, is learn what you can about the customer's internal issues, then have an experienced and diplomatic manager of your own play a few rounds of golf with the customer's C-suite. There may be some good reasons for the resistance you're facing. Or "understandable" reasons.

(Not saying that diplomacy is easy, nor that favorable results are assured.)