After a little diagnostic work (involving jump leads) the culprit was found to be...
Battery lead. It would appear that the extra strain brought on by the cold weather and the inability of the lead to carry the charge has slowly been draining the battery. Though not particularly low in voltage it would appear that it was depleted just enough to cause the car not to turn over/ fire up.
Halfrauds tomorrow for a new earth and battery lead. Thanks for all the advice, will certainly know how to keep an eye out for further developing problems
