Thanks both - my wife actually got it shortly after I'd posted it!!! Something about the Law of S*d I believe. She guessed "antediluvian" and we looked up the French.
Re. French News they are sometimes rather sneaky. 18D is Electra (English) but should be Electre (French but this doesn't fit with the A of 28A (Debasement) while one version of Andre Maurois gives Immortal rather than Eternal!!
Until we can check with our French daughter-in-law what are the horse-tails found in the hedgerows 1D (%) P*E*E?
Regards
Thanks again. My wife, yet again, ploughed through Larousse with all the P*Es and found prele which via Google gave horse-tail fern. It's really a bog and marsh plant - hardly a hedgerow as in the clue. The setter is no botanist either!!!