A tit but what type of tit?

Question

I just photographed this bird in my garden in Surrey on 23rd January 2021. I've had four different suggestions as to what it is: 
 
 1. A Great Tit that has been in a fight or is moulting (though that would be odd at this time of year) 
 2. A Blue Tit but with a facial deformity of some sort. 
 4. A Crested Tit 
 3. A cross breed of some sort. 
 Does anyone have an identification they're confident about? Never seen this bird before and am intrigued. We get hordes of Great Tits, some Long-Tailed Tits, the occasional Blue Tit and Coal Tit. 
 Thanks in anticipation

Clare · Accepted Answer

Definitely a blue tit, but I don't know what has happened to it.

rspbailey · Answer

Yes a Blue Tit which looks like it has some mite infection which has affected its feathers (which still could grow back depending on the infestation) - if so it shouldn't harm the birds ability to feed and mate.