I think it is likely to be a Harlequin Ladybird - the great invader - they do vary quite a lot and seem to be easily the most common around my garden nowadays (Sheffield, UK)
Thanks for your reply, I did wonder if it might be by the unusual pattern on it's back. It was however quite small and I had it in my mind that the Harlequins were generally bigger than our native Ladybirds....
As always many thanks Episcophagus. My garden is very rich for native Ladybirds and this is the first positive ID on a Harlequin in the garden so I do hope that it doesn't mean an explosion of them threatening my native ones?
We have an extensive wild flower area which attracts all manner of insects so from what I have just read it's an ideal dinner table for Harlequins!?