Keiran Pedley works for the polling organisation GfK NOP, which for many years now has not conducted voting intention polls (at least not for publication), but has had a hand in the broadcasters' exit polls on general election night. He also presents the podcast Polling Matters, which in spite of its unfortunate association with a certain website is often a fascinating and enlightening listen. But aside from his expertise when he has his impartial pollster's hat on, he also appears to be a member of the Labour party, and had very strong views about the possibility of Jeremy Corbyn becoming leader and the potential impact on his party's electability. It's within that context that his assertion that Corbyn "is not going to lead Labour into the 2020 election" should be seen, because the reasons he gives smack of extreme wishful thinking...
1) "He will be 70 going into the general election." So what? Many of the potential candidates for the US Presidency are envisaging holding the office at a much older age than 70. If Joe Biden stands and is elected, he will be 74 by the time he is sworn in. Ronald Reagan, of course, was almost 78 when he finally left the White House.
2) "It is not even clear he wants to be Prime Minister." I sometimes wonder if Corbyn's opponents are mistaking his natural modesty and caution for a lack of commitment. But even if there's any truth in the suggestion that he doesn't want to be PM, it could be just as easily argued that he doesn't want to be Leader of the Opposition - yet here he is. The reason he put himself forward as leader is the same reason for thinking he'll try to remain in harness for a lengthy period - he feels a sense of duty to his wing of the party, which has been frozen out of influence for so long. He knows the consequences of stepping aside could be a return to New Labour, a prospect that would fill him with disgust. He might only be tempted to retire if it looked like, at worst, a soft left candidate (Lisa Nandy's name is sometimes mentioned) would replace him. To get to that point may require reform of the nomination rules for leadership elections.
3) "His initial poll numbers are dire." The polling done since Saturday has been extremely limited, but in any case, history is littered with leaders who struggled on to a general election in spite of it being obvious they would lose - Michael Foot in 1983, John Major in 1997, William Hague in 2001. In many ways, what happened to Iain Duncan Smith was the exception, not the rule. Even he came amazingly close to surviving in the decisive ballot.
None of this is to say that Corbyn will definitely make it through to 2020 - there are plausible scenarios that could see him deposed, possibly even before Christmas. But to suggest it's a foregone conclusion that he'll go just seems daft to me. I also think Pedley is barking up the wrong tree in thinking Alan Johnson is a viable 'unity' candidate who could replace Corbyn. Labour right-wingers are going to have to come to terms with just how far to the left the membership has shifted - it will now take someone from the soft left to unite the party, not a Blairite with a working-class accent.