What you can say is that Labour lost the last election and will continue to lose elections in the future unless they listen to the electorate.
This is a short reminder:
The question is what it means to listen. The Tories' data scientists and propagandists "listen"
very closely to people, by spying on them and polling them. They've uncovered vast reserves of frustration and have become experts in channelling it into spiteful, racist policies that render it harmless to the wealthy but very dangerous to marginalised people and the fabric of society as a whole.
For a long time Labour has listened to the same noise and said, "How awful these people are! But in order to help them we must first listen to their awfulness and find ways to appease it!" Obviously this can't be done and it just helps the Tories, who can really commit to racism and spite. In any case, both the Tories and Labour have listened very intently to people - in the same way that conmen listen to marks (Tories), or cops listen to drunks (Labour), for signs of weakness or impending violence, with a view to manipulation and pacification.
What Corbynism failed to do, despite some good intentions, was to build frameworks for
actually listening to people - that is, for allowing people to come together and discuss matters that are important to them knowing that they could directly influence events.
That kind of listening really puts the sh_ts up both the right and the centre. They will not countenance it and one of the reasons they came together together to fight Corbyn was that they sensed that this was the way things were heading: open selection, constitutional convention, workers on boards, no no no! Tories are instinctively aware that if people actually feel empowered they're going to demand real change, of the type that threatens privilege. Centrists are very committed to the idea that people are malicious idiots whose lot can only be improved by an enlightened caste i.e. themselves.