Blue headed Wagtail or possible Channel Wagtail

Spotted an interesting Yellow Wagtail at Audenshaw today.Initial thoughts were it was a Blue Headed Wagtail but the head is on the pale side and with this amount of white on the throat it could be a hybrid between Yellow wagtail and Blue headed wagtail- A so-called Channel Wagtail. Also present were nominate British Yellow wagtail, White Wagtail, Wheatear the first Swifts of the year, Great Crested Grebe and  Common Sandpiper