We’ve explored the “Kinnock Factor” previously on this site, but some numbers from the latest YouGov weekly polling surprised even us today. Labour’s lead over the midterm Conservative-led government is still falling – to just 6% this time – and Ed Miliband’s personal ratings are even worse than David Cameron’s, but that wasn’t it.

You’ll probably want to click on that image to enlarge it.

The headline figures aren’t exactly an earth-shattering shock:

David Cameron net approval rating (UK): -20

Ed Miliband net approval rating (UK): -34

But the Scottish sub-sample is startling:

David Cameron net approval rating (Scotland): -39

Ed Miliband net approval rating (Scotland): -34

Now, as we’ve noted on a few occasions, sub-sample results (144 people on this occasion) are next to worthless for measuring anything with any precision or nuance. But even the crudest broad brush ought to reflect the fact that Scotland is a vastly more Labour-friendly region than the UK as a whole, and for Miliband to be rated no higher north of the border than he is in the national numbers is close to astonishing.

(Just 18% of Scottish respondents thought he’d “provided an effective opposition”, and only 20% thought he “would be up to the job of Prime Minister”, although 39% identified themselves as Labour voters. Even if we allow an enormous 50% margin of error for the small sample size those are terrible stats, maxing out at fewer than a third of voters.)

Cameron’s rating among Scots is twice as bad as in the whole of Britain, as you’d expect. But even factoring in SNP voters, for Scotland to have such a low opinion of a Labour leader makes a mockery of the notion that Miliband can lead his party to victory in 2015. Get ready for a Tory government until at least 2020, folks.