One in five people who previously voted Labour are "more likely to vote Conservative next time"?
Well, according to the same research, over one third of SNP voters, around one third of Lib Dem voters, about one fifth of UKIP voters, and eight per cent of Conservative voters are more likely to vote Labour now that Corbyn is Leader.
UKIP and the Lib Dems did badly enough last time, without losing one fifth and fully one third of their respective support.
The SNP has a lot to live up to, and it will not do so if it has lost more than a third of its vote.
And the Conservatives scraped in so narrowly that they cannot afford to risk losing eight per cent of that, even in return for one fifth of the smaller Labour vote last time.