Bird of prey id ?

This is about buzzard size and redder than it appears in the photo, it’s tail feathers are unusually long, banded white and dark.

I thought it was a juvenile red kite until it flew up into the tree and I saw it’s tail feathers.

Picture took on farmland on the notts/lincs border this morning.

It has baffled me and I’m usually quite good at native birds, could it be a Harris hawk? Are they breeding in the Uk ?

Any suggestions would be greatly appreciated.