There's been such a drought of polling recently that I was beginning to think we weren't going to get anything more until the end of the English school holidays. However, a Britain-wide YouGov poll suddenly appeared today, suggesting that Labour's very narrow lead over the Tories has stabilised after falling from a peak of 8 points in early July. The Scottish subsample continues to show the now familiar tight three-way battle: Labour 33%, SNP 29%, Conservatives 28%, Liberal Democrats 7%, Greens 2%, UKIP 2%.
The most significant thing about those figures is that the Tories are in third place, which has consistently been the case in all four post-election YouGov subsamples. The lead has been switching back and forth between the SNP and Labour, so it's anyone's guess which of those two parties would be in first place if YouGov conducted a full-scale Scottish poll of Westminster voting intentions right now. An average of the four subsamples produces an exact dead heat: SNP 32.3%, Labour 32.3%, Conservatives 26.3%, Liberal Democrats 6.0%.
On a more positive note, the SNP have had the lead in the majority of subsamples conducted across all firms. There have been fourteen subsamples since the election, with the SNP ahead in eight, Labour in five, and the Tories in only one. The SNP have been in either first or second place in all fourteen subsamples, whereas both Labour and the Tories have been in third place in some - underscoring the general impression that the SNP are the party most likely to have a small overall lead.