'Back in February these polls – from Ipsos Mori, YouGov, ComRes and Survation – reckoned on average that just under three-quarters (74%) of those who voted Labour in last year’s general election intended to vote for remain. In short, it was apparent from the very beginning that a substantial minority of Labour supporters were disinclined to follow their party’s recommendation to back remain.
The early months of campaigning simply saw this pattern maintained. When these four polls were conducted in mid-May, again on average 74% of Labour supporters indicated that they would vote remain.
When these polls produced their final estimates on the eve of polling day, support for remain among Labour supporters had eased back a little, but still stood at 72%. Moreover, this was against the backdrop of a marked drop in the overall level support for remain, a drop that was especially in evidence in polls conducted by phone, which account for three of the four polls examined here.
Far from being especially marked amongst Labour supporters, it was amongst Conservative voters that the fall in support for remain during the campaign appears to have been heaviest.
Earlier in the campaign our four polls suggested Conservative supporters would divide roughly 50:50 between remain and leave. In February 48% of them said on average that they would back remain, while in May the figure was 51%. However, by the time polling day was approaching support for remain had fallen back to 44%.
Of course, if Labour had fought a more enthusiastic and effective campaign in favour of staying in the EU then maybe support for leaving among its supporters might have been whittled down. But it is also open to doubt whether many of the working-class “left behind” voters that formed the core of leave support would have responded to such efforts.
In truth, if the finger of blame for remain’s defeat is to be pointed anywhere it is better directed at the prime minister rather than Corbyn. David Cameron failed to bring his party with him at all, and in the event that simply proved too much of a handicap for the pro-EU camp to overcome.'
From a Guardian article on 4th July.
Not that I expect anti-Corbynites to believe it.