Pure Azure?

Very interesting bird!  Does this Azure Tit look-a-likey have some Blue Tit in it?  What's it doing in Buckinghamshire, in late August-early September?  Do people keep them as cage birds?  Lots of questions surround this bird however stunning it looks.

Edit - so it would appear, thanks to local birders investigations, this is an escaped Yellow-breasted Tit.  Close, but no Arctic cigar!