Oh, they would be good shots for the mystery photograph in British Birds magazine
You've only got two well defined features to go on.
1. the notched tail - good for Linnet
2. the shape of the bill - the upper edge is virtually straight, the lower edge has the slightest of curves, also good for Linnet
Given the angle of the light colouration is rather washed out, however they do not appear to be very heavily streaked below. Redpoll and Twite, the latter possible in your part of the world if it is still cold further north (I seem to think you are north of England based), would both show heavier streaking below. Both tend to have yellow bills, although that of the Twite is darker in winter and I think there would be evidence of the little black bib that the Repoll possesses, so by a process of elimination I would plump for Linnet.
many thanks ... yes, not much to go on, at full zoom and with the light nearly behind and heavily PP'd to get them as "good" as this ... streaking a bit more obvious in the flesh (or feather) .... Twite would be a nice catch down here, Barrie ... I'm about one degree further North than you ...