The polling mystery deepens. Last Sunday YouGov reported that they had identified a swing to Yes for the third poll in a row, while on the very same day Panelbase indicated that nothing had changed at all. Then on Tuesday TNS BMRB agreed with YouGov that there had been a substantial swing to Yes – only now for Survation to say in a poll for tomorrow’s Daily Record that they too have failed to identify any swing.

Of course what Panelbase and Survation had in common – and what distinguishes them both from YouGov and TNS BMRB – is that they have been reporting that the referendum race is relatively close for some time. They both continue to do so. But their failure to identify any swing does mean that what we have seen in the recent polls is convergence rather than an unambiguous movement – though, crucially, a convergence on a position that says the referendum race looks tight indeed.

Survation’s poll tonight finds that Yes are on 42%, No on 48%. Both figures are unchanged from the company’s previous reading taken a fortnight ago, shortly after the second of the two leaders’ debates. Once the Don’t Knows are left aside, Yes are on 47%, No on 53%, again unchanged from the company’s previous poll. Indeed this is the fifth time that Survation have put Yes on 47%, a figure it first reported in June. It represents the company’s all-time high for Yes.

On the one hand this result will clearly come as a disappointment for the Yes side, who would have hoped that this poll would replicate the swing identified by YouGov and TNS BMRB, and thus prove to be the second poll in the campaign to put Yes ahead. On the other hand, these latest figures hardly suggest there is any room for complacency in the No camp. They confirm that the Yes side is doing at least as well as it has at any point in the campaign, and is breathing (as it may have been for some time) down the No side’s neck.

Meanwhile, today’s poll has no impact on our poll of polls, in which Yes remain on 48% and No on 52%. That means Yes remains at its highest level in our series, which now extends across the whole of the last twelve months.

About the author

John Curtice is Professor of Politics at Strathclyde University, Senior Research Fellow at ScotCen and at 'UK in a Changing Europe', and Chief Commentator on the What Scotland Thinks website.