Support for independence breaks through psychological barrier in new TNS-BMRB poll

When the SNP's Kevin Pringle teased us earlier tonight about a forthcoming "encouraging" poll, I wondered if it might be the overdue monthly poll from Survation for the Record.  But in fact it's the latest poll from another monthly series - the one conducted by TNS-BMRB.

Should Scotland be an independent country?

Yes 30% (+1)
No 42% (+1)

TNS of course use a methodology that for some reason finds far more Don't Knows than any other pollster, and this is the first time the Yes vote on the headline numbers has been in the 30s since that methodology was introduced.  The No lead also remains at the record low of 12% that it fell to last month - less than half of the peak lead of 25% that TNS reported in the autumn of 2012, and barely over half of the 22% lead they reported as recently as last September.

If you pump the above numbers into a calculator, it looks as if the Yes vote with Don't Knows excluded ought to be 42%, which would be a record high from TNS during the campaign period.  However, it appears from John Curtice's blog that the rounding has cheated us of that -

Yes 41% (n/c)
No 59% (n/c)

It may well be, though, that when the datasets appear we'll find that the gap has indeed narrowed a smidgeon on the unrounded numbers.  And we already know that the No lead has slumped to single digits among respondents who say they are certain to vote -

Yes 35% (+2)
No 44% (-2)

Those numbers are identical to the record low No lead of 9% that was reported in late January on the same measure, which has proved considerably more volatile than the headline numbers.  But other than that January poll, the No lead among certain voters has only fallen below 13% once, so this could well be a significant moment.  When Don't Knows are stripped out, the figures work out as something in the region of 44% or 45% for Yes - much more in line with what the more Yes-friendly pollsters have been showing on their headline numbers for months.  (And remember if this was Ipsos-Mori the figures for certain voters would be the headline numbers.)  Coming from one of only two non-online pollsters, that's massive - but only if it doesn't prove to be another January-style blip.

The Curtice spin on this poll fits neatly into the narrative he's been nursing in recent weeks of "there was momentum for Yes during the winter, and they've consolidated that in the spring rather than building on it further".  I must say that seems like a slightly odd reaction to this particular poll.  42% for No is an extremely typical figure that we've seen no fewer than five times before in recent months from TNS.  But Yes have never been as high as 30% before (at least not since the methodological change), and indeed have only been as high as 29% on three occasions.  So that suggests to me that further progress is being made.  As for the slump in the No lead among certain voters, Curtice casually brushes that aside and accuses TNS of only drawing attention to it in order to make a "no change" poll look more interesting.  Perhaps he hasn't noticed that the figures for certain voters have been on prominent display on the TNS website for months now?

In spite of the fact that TNS have shown a hefty swing to Yes since the autumn, they do of course remain one of the more No-friendly pollsters, and that has to be borne in mind when trying to make sense of these numbers.  A 41% Yes vote from TNS with Don't Knows excluded could well be the equivalent of a 47% or 48% Yes vote under the Panelbase or ICM methodologies.  The million dollar question is who (if anyone) is getting it right - and, scarily, we won't be sure of the answer to that until polling day.  It's quite conceivable that by September some pollsters will be showing a Yes lead while others will still be showing a No lead, and we genuinely won't have a clue whether Scotland is about to become an independent country or not.

The other health warning that always has to be put on TNS polls is that their fieldwork is generally quite a bit out of date by the time they actually get round to publishing. So these numbers probably won't wholly factor in the impact (if any) that the anti-independence cinema advert has had, and they'll entirely exclude any impact of the utterly barmy newspaper ads from the fake "grassroots" Tory-funded group Vote No Borders.  Is it just me, or has the Yes campaign suddenly fallen slightly behind in the advertising wars in recent days?

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SCOT GOES POP POLL OF POLLS

In line with the trend shown by TNS, both sides edge upwards in this update of the Poll of Polls headline numbers, with Yes reaching the giddy heights of exactly 36%, and with the No lead remaining at a record low of 11.2%.  Once Don't Knows are stripped out, though, the No lead has dropped even further.

Of course Ipsos-Mori are still represented in this sample by their last published poll, which was conducted in the late winter.  If we were able to replace that poll with the notorious secret mega-poll they conducted for the Cabinet Office recently, it might well be that the No lead in this update would be somewhat lower than 11.2%.

MEAN AVERAGE (not excluding Don't Knows) :

Yes 36.0% (+0.2)
No 47.2% (+0.2)

MEAN AVERAGE (excluding Don't Knows) :

Yes 43.3% (+0.1)
No 56.7% (-0.1)

MEDIAN AVERAGE (excluding Don't Knows) :

Yes 43.6% (n/c)
No 56.4% (n/c)

(The Poll of Polls is based on a rolling average of the most recent poll from each of the pollsters that have been active in the referendum campaign since September 2013, and that adhere to British Polling Council rules. At present, there are six - YouGov, TNS-BMRB, Survation, Panelbase, Ipsos-Mori and ICM. Whenever a new poll is published, it replaces the last poll from the same company in the sample. Changes in the Poll of Polls are generally glacial in nature due to the fact that only a small portion of the sample is updated each time.)

Here are the long-term trend figures, with the updates prior to Easter recalculated to exclude the inactive pollster Angus Reid...

The No campaign's lead in the Poll of Polls headline figures :

Sep 2013 - 21.6%
Sep 2013 - 21.4%
Sep 2013 - 19.4%
Oct 2013 - 18.8%
Oct 2013 - 18.4%
Oct 2013 - 18.2%
Nov 2013 - 18.4%
Nov 2013 - 18.0%
Dec 2013 - 17.0%
Dec 2013 - 16.8%
Dec 2013 - 16.4%
Jan 2014 - 14.4%
Jan 2014 - 14.2%
Jan 2014 - 14.2%
Jan 2014 - 15.2%
Feb 2014 - 15.0%
Feb 2014 - 15.5%
Feb 2014 - 15.5%
Feb 2014 - 13.7%
Feb 2014 - 13.3%
Feb 2014 - 14.2%
Mar 2014 - 14.2%
Mar 2014 - 14.5%
Mar 2014 - 14.5%
Mar 2014 - 14.7%
Mar 2014 - 13.8%
Mar 2014 - 13.0%
Mar 2014 - 12.5%
Apr 2014 - 12.5%
Apr 2014 - 12.7%
Apr 2014 - 12.7%
Apr 2014 - 12.3%
Apr 2014 - 11.4%
May 2014 - 11.2%
May 2014 - 11.2%