Leven, Kennoway and Largo by-election result, 15th December 2016 :
SNP 37.0% (-4.0)
Labour 28.4% (-6.9)
Conservatives 18.5% (+11.7)
Liberal Democrats 14.3% (+4.3)
Greens 1.8% (n/a)
Things have come to a pretty pass when Labour are quite genuinely 'celebrating' a defeat in a former heartland, a 7% drop in their own vote share, and a 1.5% net swing from Labour to SNP. But it's probably fair to say that, in the context of the times, this is a tolerably good result for them. If extrapolated nationally on a 'just a bit of fun' basis, it would put them only a few points behind the SNP. The snag is, of course, that there is absolutely no evidence from any opinion poll or from any other recent by-election to suggest that their resilience tonight is anything more than a freakish one-off. The chances are that there were local or personality factors that worked in their favour in this particular contest.
Should we be at all concerned about the slippage in the SNP vote, given that the party had only a modest national lead in the last local elections in 2012? A loss of support is certainly more noteworthy in this sort of by-election than it would be in areas of traditional Tory strength - we can't just neatly put it down to a small number of No-voting ex-SNP supporters finding a way of resolving their cognitive dissonance. However, the most recent national opinion poll (conducted only two or three weeks ago) gave the SNP almost half of the popular vote, and in spite of the question marks that now hang over the polling industry, it's unlikely that polls would completely fail to detect a dramatic shift in public opinion.
The small increase in the Liberal Democrat vote is very much in line with last week's Scottish local by-election, the parliamentary by-election in Sleaford and North Hykeham, and also a couple of Britain-wide opinion polls. So there does seem to have been a genuine post-Richmond Park bounce for the party. The problem is that they'll need to follow up that win at some point if they want to maintain their momentum, and respectable third or fourth place finishes aren't really going to be enough. The afterglow of a single by-election success - no matter how spectacular - is generally pretty short-lived, and if what we're seeing now is as good as it gets for the Lib Dems, they're not really back in the game in any meaningful sense.