- many thanks for all the posts, the advice and the definitive ID
from rbel - google images confirms it's a ringer for Rana esulenta.
What wasn't evident from my pic were its enormous back legs, easily 3
times the width of his body and I took the libery of giving it a tiny
prod whereupon it jumped a froggy mile.

Anyway, I'm hoping it's forgiven me now that I've built it a glorious
swimming pool. Let's hope it doesn't dry out before my return, the
forecast for next week suggests a bone-dry scorcher.