The Labour right and their friends in the media are constantly urging the party to become more regressive to appeal to Reform voters. As we’ve reported in the past, though, Labour actually lost four times as many voters to parties on its left. And now, we have a clearer picture of what pushed them in that direction.   EXCLUSIVE: More than half of former Labour voters who intent to back a centre or leftwing party in the next general election have cited the government's record on Gaza as a reason for abandoning Labour, new polling shows. — Harriet Williamson (@harriepw) June…