The answer isn’t going back to the left of the Corbyn era, but it isn’t gutting the party of the left either.
Labour can be an electable party that places itself to the centre whilst running on popular leftist policies.
Nobody seems to realise this and whilst there’s continuing infighting from both sides things will just get worse.
Two quite simple things he could do, which would resonate with millions, post pandemic.
#1. Say he would ring fence the entire covid spend, remove it from the Govt accounts, and pay it back over decades, to allow future administrations to function in a more normal way.
#2. Say he would instruct HMRC to not pile into the recipients of the self employed support scheme, tax notwithstanding, to prove they should have had it. The questions they asked were so ambiguous to qualify, means they are equally as easy to disprove.