A few days before voters went to the polls on Thursday, the Labour MP Neil Coyle was out campaigning in his Bermondsey and Old Southwark constituency. A man answered the door and told Coyle bluntly not to bother leaving a leaflet because he regarded his leader as a terrorist sympathiser and wanted nothing to do with him, or anyone associated with Labour.

On another occasion, Coyle was confronted by a father on the school run who turned the air blue in front of his own child, using a four-letter word to sum up his view of Jeremy Corbyn. “There were people who said they knew Boris Johnson was a liar and a cheat but they still preferred him over our leader,” Coyle said.

He and his team talked to 10,000 people during the campaign and kept a record of what each of them said. The two reasons most often given by those who decided against Labour were its policy on Brexit and dislike of the leader. “Dislike of Corbyn came top,” added Coyle, who was one of the Labour survivors on election night. He retained his south London seat with a big – though reduced – majority. But for hundreds of other candidates, including many fighting Labour target seats, countering the Corbyn factor proved impossible.

Journalists who went on the campaign trail were struck constantly by the force of anti-Corbyn feeling on doorsteps. On a visit to the target seat of Norwich North, halfway through the campaign, the first voter I encountered when following the impressive Labour candidate Karen Davis round a housing estate dismissed Corbyn as a “twat”.

Despite the overwhelming evidence, team Corbyn denies completely that it was the leader who repelled voters

For half an hour afterwards Davis, who has a job in charge of social inclusion on the local council, seemed reluctant to knock on more doors with me, and let her helpers face the voters instead. It seemed to me that she knew, from bitter experience, that the next responses were likely to be just as hostile. As we walked round, she told me that there was lots of poverty in that part of Norwich and that she would be returning to many of the same houses after polling day in her social inclusion role, a tacit admission that she held out little hope of becoming an MP.

Norwich North was near the top of Labour’s target list. But none of Davis’s literature mentioned Corbyn at all. I approached a man in his garden on the same Norwich estate who said: “I have voted Labour all my life but I can’t stand Corbyn and won’t vote for him.” Davis came over and urged him to change his mindset and think of the Corbyn leadership as a “management blip” as she did her best to talk him around.

Facebook Twitter Pinterest Jeremy Corbyn leaves his home in Islington on Saturday. Photograph: Isabel Infantes/PA

Up and down the country, Labour candidates were all too aware what their biggest problem was. But they had to keep quiet about it while campaigning. One Labour MP told me on Friday morning, after details of Labour’s catastrophic defeat were known: “We all knew what was coming, just not quite how bad it would be. We didn’t want to allow the Corbynistas and Momentum to blame us and point the finger at us afterwards, so there had to be an unspoken agreement to deny it.”

Many Labour MPs had been observing this same vow of silence about Corbyn for more than three years, since they mounted a failed coup to oust him in 2016. They thought there was nothing for it but to allow him to fail on his own.

When shadow health secretary Jonathan Ashworth was caught on tape, in the last few days of campaigning, telling a Conservative friend that it was looking “dire for Labour” because of a “combination of Corbyn and Brexit”, he was only saying what fellow candidates had known all along.

The Observer’s pollsters Opinium have revealed their own analysis of the reasons people rejected Labour: 43% cited the leadership, 17% its policy on Brexit, and 12% its economic policies. Among Labour defectors – those who voted Labour in 2017 but didn’t this time – 37% mentioned the leadership, 21% Brexit and 6% its economic policies.

Clashing egos and 'policy incontinence': inside Labour's campaign Read more

Despite the overwhelming evidence, team Corbyn denies completely that it was the leader who repelled voters. Corbyn, when acknowledging Labour’s defeat in the early hours of Friday, refused to accept any personal responsibility for his second general election loss, and said he would stay in office during a “period of reflection”, before stepping down. He, shadow chancellor John McDonnell and party chairman Ian Lavery all insisted Brexit had drowned out Labour’s popular policy agenda, and that the leader had not been the problem. This has infuriated MPs and defeated candidates, who see it as evidence of the Corbynistas’ determination to hold on to the levers of power in order to install a successor in exactly the same mould as Corbyn who will deliver more of the same.

Many of those who daily felt the full force of anti-Corbyn sentiment will not let them do so without a fight. The recriminations began in the early hours of Friday. After retaining his Wolverhampton South East seat by a whisker – despite a 9.88% swing from Labour to the Conservatives – the Labour MP Pat McFadden issued an existential warning to his party. Both Corbyn and Corbynism had to go. “The most disastrous thing we could do is carry on with Corbynism with a new face,” he said, as the bloodletting began.