There weren’t many of those to be fair.
40% of the electorate in 2017, 32% in 2017. By comparison, Tony Blair's last victory for Labour in 2005 won 35% of the vote.
All who voted Labour in 2019 by definition "voted Corbyn". Is @MarshaBradyo seriously claiming that the Tories will make no effort whatsoever, and put no thought into, winning over previous Labour voters in any seats? That would be a first for a major political party strategy.
As for what Cons voters feel, that's what concerns me really. This thread is an interesting example of what I find to be a common phenomenon:
www.mumsnet.com/talk/am_i_being_unreasonable/4659407-any-tory-voters-here-who-are-switching-to-labour-this-time?reply=120952449
There are some who say they've voted Tory all their life but the Tories are just too far beyond the pale now and they can't. Some of those will vote Labour because they can get behind Starmer (yay Keir). Quite a few who say they will just never vote Labour under any circumstances ever (so really makes no difference whether it's Keir or Jeremy, or whoever in between).
But the sense I get, on that and other threads, and elsewhere, is of people trying really hard to still find an excuse to vote Tory. "I can't vote for a party that doesn't know what a woman is". "I can't vote for Angela Raynor". "It's just as bad in other countries". "It wasn't Boris's faul war broke out in Ukraine!" There seems to be roughly a third of the electorate that are drawn to the Tories by some kind of primal magnetic force that would take a once-in-a-millenium seismic cleft in the order of nature to disrupt. Don't ask me to explain it, it's like some kind of weird masochistic dependent relationship. But there you go.
It was quite an achievement on Johnson's and Truss's part to be SO UNPRECEDENTEDLY AWFUL that even some of these people felt they couldn't go on with it. And to be fair, no small achievement on Starmer's part to consistently manage his centrist Tory-friendly brand so well that he could soak a lot of them up.
But all those people need is one little excuse to go back to their comfort zone, and I fear the Tories finally putting an apparently capable, respectable and intelligent human in charge of the country will be that excuse.