Also known as the small cabbage white, it is a common and widespread species. In the UK, numbers are boosted by visiting individuals from mainland Europe. The underside of the wing is a creamy yellow colour. This individual I'm sure is a male due to the size and position of the wing spots.
Seen almost everywhere, from the countryside to towns.
I found this butterfly fluttering along the Wivenhoe Trail between Colchester and Wivenhoe.