on plumage I'd go for juv. grey, however that massive bill was more what I was looking at first time round!! It is probably slightly deformed anyway so any plumage abnormalities could be explained using that theory.
Given the time of year it can't be a juv. I think its a Grey Heron with soiled plumage. Structurally, it doesn't look anythink like a Purple Heron.
A strange bird indeed, My apologies for creating any hysteria in sleepy Leicestshire.
Would love to some better photos of the bird as mine were taken through a scope with a phone and don't portray it all that well.
My assumption on Purple heron was not made alone nor was it made lightly, Also was seconded by other birders, Just in case anyone is feeling a bit grumpy because they missed there barbies and burnt some diesel
Karpman
Aka. Ryder Hurn