Keiran Pedley on the sensational survey for the Times

Last night, YouGov released a poll on the Labour leadership that has thrown something of a hand grenade into the contest. After rumours that private polling was showing Jeremy Corbyn ahead we now have a poll showing exactly that. In fact, the first preference numbers in this poll are:

CORBYN 43%
BURNHAM 26%
COOPER 20%
KENDALL 11%

Not only does Corbyn win on first preferences (and by a country mile) but on these numbers he actually wins the entire contest, beating Andy Burnham by 53% to 47% in the final round.

When sensational polls such as these are released they usually cause a sensational reaction. We can expect nothing less from this poll but it is worth pausing and considering how much weight we should place on these results. At the time of writing we have limited information on methodology and no data tables so for now here are some thoughts which I will likely update at a later time once we have more information.

The problem with this poll is that we are not likely to get many others to compare it to. It will stand alone as the voice of the Labour (s)electorate until there is another one. Given the results, it will undoubtedly shape the immediate agenda in the Labour leadership race as candidates seek to respond to these numbers and establish or re-establish momentum.

On this point I have some sympathy for Lord Foulkes. This one poll will shape the immediate political agenda but as any pollster will tell you it is still ‘just one poll’. In an ideal world there would be several others to compare to (though I suspect this is unlikely). Corbyn’s lead could be exaggerated. We have learned from the Scottish referendum and General Election that focusing on one poll showing ‘Yes’ ahead or a couple showing ‘The day the polls turned’ is folly. Perhaps the media hasn’t learned.

It is worth remembering that this is a very difficult audience to poll. Getting a representative sample of the wider electorate is hard enough (as we pollsters well know by now) but doing so of those choosing the leader of a political party is even harder.

There are many variables to control for. For a start, we have the usual issues of age, gender and region for which YouGov would need to know the makeup of the Labour membership. This ought to be fine if you have that information but there are other more complex issues to address such the balance between affiliates, Trade Union members and party members and also when Labour members joined the party. All of which, if skewed, could impact the final result. Also, as an aside, building a large enough body of Labour members on an online panel is quite a challenge. Personally, I would love to know how many they have.

It is very brave of YouGov to release a poll like this at this time. I know the team at YouGov, if anyone can do it they can but it is a very difficult job. After all, the pollsters face a tough time at the moment given the 2015 General Election polling disaster and subsequent BPC inquiry. It will be interesting to see if they release any more of these and how close to the day of the result. Of course, there is not a ‘polling day’ as such so it is different to General Election polling.

Corbyn ahead – for now

So what do the results actually mean? Well clearly we should take the prospect of a Corbyn win seriously now. It could be the ‘vent before the vote’ of course but it is clear that the Labour membership has little time for a move to the centre. I have made my thoughts on this known here. It is, however, worth considering that even being so far ahead on first preferences Corbyn only narrowly wins overall. This means he must suffer once second preferences are reallocated and that he needs a big lead on first preferences to actually win. It could be that this poll overstates his position, or that his lead decreases over time. Either way, although this poll is sensational, I still do not think he will win. The difference now is we really cannot be sure of that.

Keiran Pedley is an elections and polling expert at GfK and tweets about politics at @keiranpedley