Hi Edward,
Firstly,let me point out that I'm not perhaps the best person to give advice with pipits,as I've only ever seen three species here(Meadow,Rock and Richard's)and have very limited experience of any other species abroad(have seen Tawny well in Bulgaria,but only had Red-throated as fly-overs and most of the Trees that I saw there were fly-overs also)
Nevertheless,I'll give my opinions,for what they're worth...
Firstly,let's start with what it's NOT!From these shots,the larger pipits(Richard's/Tawny/Blyth's)can easily be ruled out,as can Rock/Scandinavian Rock/Water/Buff-bellied,so we're left with one of the smaller pipits:Meadow,Tree,Red-throated,Olive-backed or Pechora.
Of these,we can eliminate Olive-backed and Tree on account of the thickness of the flank streaking(very fine on these two),also neither should look so greyish(esp.OBP),and neither have a long hind claw as this bird does(best seen in bottom right photo)
Pechora is really quite distinctive,and doesn't appear to vary too much,so can be ruled out in this case,leaving the two candidates to spring to mind when I first saw the photo:Meadow and Red-throated.
In my opinion,this bird is most likely just an odd Meadow Pipit,despite superficially resembling RT.A "classic" Red-throat should have distinct whitish "braces" on the mantle:this bird seems no better marked above than most Meadows.Also,one would expect a spring Red-throat to have far more red on the face by now(not sure about 1st-s,but one would presume that they obtain red during the winter).Greyish Meadows occur quite regularly,especially in Iceland and Scandinavia,and such birds can also show warm tones to the throat.
If the bird is still around,or if more photos are forthcoming,it would be advised to check out the rump pattern:more or less unmarked in Meadow,but distinctly streaked in Red-throat.
Also,the flight calls of the two species are really quite distinct(Meadow has the well-known "sip",often given as a series "sip-ip-ip",Red-throat has a drawn out "pseee",a bit like letting air out of a tyre)
I am quite willing to admit that I may be wrong!
ATB,Harry H