Goldfinch (Carduelis carduelis)
Initially they started coming to gardens later in the winter after food supplies in the countryside were exhausted and the BTO study shows that around mid-February would see numbers in gardens build up. But that has changed now too and they can turn up at almost any time.
Definitely a seed eater, they will pay little attention to peanuts and even less to fat balls; anything on the ground is usually overlooked too. Their particular favourite is nyger seed and you can now buy it in special 'Goldfinch only' containers!
They are smaller than most finches but what they lack in size they make up for in fighting spirit. They can more than hold their own against all comers.
It being so cold I had to take this photo through the window so it is not quite as sharp as I would have liked. I will try and get a better one when the weather improves.