Well, First Prize goes to Marco1979!
Thanks for your suggestion regarding the battery, which appears to have been the problem and not something I thought was O.K.
I must have "misremembered" changing the battery a couple of years ago (must have been on one of my other vehicles) but the "eye indicator" on the top of the Jazz's battery was showing green for a good charge when in fact it was flat.
Took the battery out this morning and put it on charge for about three hours. Refitted it even though the charger had not reached fully charged indicator state and turned the key. BINGO! Engine turned and started. Put the gear lever in reverse and backed up about a couple of feet, stopped and selected drive and sucessfully pulled back to where I had originally parked. All the dash warnings have gone and the dash reads as normal without the warning (gear/exclamation mark) showing and the current mileage is correct.
Thanks again for you help.
Waiting for the road to clear of parked vehicles later today and will run the car down the road and then park in front of my garage and connect charger for an overnight charge.