That Corbyn fella...

is not what Starmer is referencing. The context is;

Sorry, posted another response before yours, but I dropped in a couple of Starmer quotes that seem to be insinuating opposition to war is support for Russia in one form or another.

It's in the Corbyn thread because it's a slight derail from Corbyn speaking at the rally and because he's the deputy president of the Stop the War coalition.

Anyone actually heard/seen/read what he said? I've not. Instead we've got a guilty by association situation (not a new criticism of Corbyn, tbf). But in this case, I don't think being affiliated with STW is anything anyone should be embarrassed about (at the moment - if they did come out supporting Russian aggression I'd reformulate my position).