Daily polling roundup 19th April

This weekend we got three new national polls, two from YouGov for the News UK papers and the weekly Opinium/Observer poll. Opinium’s fieldwork began just before the debate, with “most” responses after it:

A few hours later, YouGov/Times found:

CON 33 (-1)
LAB 36 (+2)
LIB 8 (-1)
UKIP 13 (-1)
GRN 5 (=)

Fieldwork was 17th-18th. Then tonight we got a further YouGov poll for tomorrow’s Sun, showing the parties pretty much back to even:

So what actually happened? Well, we won’t get the tables to tonight’s YouGov poll until the morning, but there’s a clue in last night’s question about the debate. 20% of respondents watched the entire debate, including 25% of Labour voters and 15% of Conservative voters. But the BARB viewing figures showed an audience equivalent to only about 9% of the electorate. About 28% said they saw some of the programme or clips or it, but since the figures were pretty similar for each party, we don’t need to worry about this group too much. If we reweight the first group down to 9% and we get revised topline figures of CON 34, LAB 34, which is very close to what tonight’s poll found.

It might be a pure coincidence, but the same thing happened after the Paxman interview – the Saturday YouGov poll showed a four-point Labour lead, but by Monday is was back to all-square (there was no Sunday poll that week). It’s quite possible that there’s a response bias in the aftermath of these types of event – we simply won’t know until we get some more polls. But what happened with Opinium? There was no debate question this time, but nothing obviously amiss – the toplines showed a 2% swing from Labour to UKIP, so the question now is whether this is real and if so, whether it will be sustained. It may well just be a blip.

And finally:

Tomorrow we get the usual Monday releases: Populus in the morning, Ashcroft in the afternoon (both polled over the weekend) and YouGov/Sun in the evening, the fieldwork for which is taking place tonight and tomorrow. Hopefully we’ll get others too…