It was taken at Stansted airport in Essex, on an expanse of grassland that is regularly cut, and has some wildflowers. Unfortunately the quality of the photo is quite poor - it was a quite a distance away and only settled for a very short period.
Thanks for the confirmation David. I thought it was due to the prominent orange spots on both the fore and hindwings, but I decided to check because I have seen on this forum just how easy it can be to confuse some lycaenid species.