The Labour leader is not taking part in the probe into what went wrong at the polls, The Independent understands, which is due to examine the root causes behind the party’s worst electoral defeat since before the Second World War.
Headed up by former leader Ed Miliband, the inquiry is expected to report that Labour was hopelessly outmatched by the Tories in its digital campaign, while activists on the ground were repeatedly confronted with concern about Mr Corbyn, insiders said.
The damning report is expected to be released on the eve of the announcement of the next Labour leader, with a source saying: “We want it to be the first thing in the new leader’s in-tray.”
The news comes ahead of the final stage of the race to succeed Mr Corbyn, with candidates facing a Valentine’s Day deadline to win sufficient support from affiliated trade unions and local parties.
Shadow cabinet members Sir Keir Starmer and Rebecca Long-Bailey, and Wigan MP Lisa Nandy have already passed the threshold to get onto the ballot paper but Emily Thornberry, the shadow foreign secretary, is struggling to make up ground.
While the leadership contest is dominating the headlines, a group called Labour Together, made up of people different wings of the party, is trawling through views from members, ousted MPs and Labour supporters on what went wrong in 2019.
Insiders said it was clear that the Tories had significantly upped their online game since the 2017 election, which meant the party benefited from people sharing its message organically, rather than through paid advertisements.
Mr Corbyn’s leadership also repeatedly featured on the doorstep, with newspaper reports on his associations with Sinn Fein during IRA bombing campaigns appearing to resonate more strongly than in the previous election.
Insiders said the report will show that voters wanted “a hand up, not a hand out” and pointed to strategic mistakes by the party leadership.
“There is a lot of anger from the left over why we did not adopt a more defensive strategy,” the source added.
The report is also expected to find it will be impossible for Labour to win a majority in 2024 without making up lost ground in Scotland – or winning deeply entrenched Tory heartland seats. “Jacob Rees-Mogg’s seat [North East Somerset] is the one that we would need to win to get a majority without Scotland,” a source said.
Sources close to Mr Corbyn said he would take part if he had been asked but no approach had been made.
More than 8,000 people have submitted evidence to the review ahead of the 21 February deadline, with gimmicky policies, factionalism and inefficiencies among the complaints raised.
An early release from the review, first published in The Guardian, found the free broadband policy was seen as “gimmicky and distracting” while digital tools were “clunky”.
But the inquiry has also attracted controversy within Labour over its decision to appoint Mr Miliband to lead, after he led the party to a poor showing in 2015.
It comes after a separate internal report, presented to Labour’s ruling body, absolved Mr Corbyn of responsibility and instead blamed Brexit and “unrelenting” media attacks on his character for the defeat.
The final version is expected to come out after the leadership election, to allow the new leader and their team to be involved.
Join our commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies