Tantalising TNS poll suggests the SNP still enjoy enormous lead

The long wait for a full-scale poll of Scottish voting intentions conducted after the election of Jeremy Corbyn is now over, with the publication today of the monthly TNS poll...

Constituency ballot :

SNP 56% (-2)
Labour 21% (-2)
Conservatives 12% (n/c)
Liberal Democrats 6% (n/c)

Regional list ballot :

SNP 52% (+1)
Labour 23% (-1)
Conservatives 11% (n/c)
Liberal Democrats 6% (n/c)
Greens 5% (-1)

The 2% drop in SNP support on the constituency ballot is not statistically significant in itself, but it must be remembered that the party's 58% showing in last's month poll was 2% lower than in any other TNS poll since the general election.  So it's beginning to look like the most extreme phase of the SNP's extraordinary post-May honeymoon is now over, and that we perhaps won't see the 60% barrier being broken again.  The good news, of course, is that we don't need that to happen - 56% is still an extraordinarily high figure that could conceivably lead to a clean sweep of Holyrood constituency seats if it is sustained over the next few months.

The other crucial point is that, on the face of it, the slight dip in the SNP's fortunes on the constituency ballot has nothing whatever to do with Jeremy Corbyn, because Labour are also down 2% - wiping out almost all of their supposed "recovery" from last month.  In theory, you could construct a case that Corbyn has won back a few traditional Labour voters from the SNP, and that those people have been more than offset by centrist unionist voters draining out at the other end to the Tories.  But if that's happened, why have the Tories not recovered even slightly from their unusually poor showing last month?  And why, indeed, has the SNP vote actually increased by 1% on the list?  It doesn't seem very plausible.  As ever, we'll need to see a couple more polls to be sure, but at the moment the evidence is strongly suggesting that Corbyn has failed to dent the SNP's strength.

The Corbyn factor was by far the biggest 'known unknown' as we pondered what might derail the SNP before May.  If we can begin to breathe a little easier on that front, what other possible obstacles still have to be faced?  The most obvious one is the Michelle Thomson affair.  The new poll is of no help in that regard, because as always with TNS, the fieldwork is a little out of date.  My guess is that the unionist media have significantly overplayed their hand with risible stories about SNP MPs owning homes (gasp!) and having stylish furniture.  But time will tell.