As soon as Remain had lost to Leave, a series of articles, tweets, and interviews from some Labour MPs suggested Jeremy Corbyn was to blame for the Brexit victory. Shortly afterwards, the majority of his shadow cabinet resigned, he lost a vote of no confidence, and faced numerous calls to step down. Fewer than three weeks later, he faces a leadership challenge from Angela Eagle.

If Corbyn is replaced, it would be disingenuous to blame this on his performance in the EU referendum. Ahead of the vote, Corbyn appeared on national television for a one-on-one interview, after having made 123 public appearances, including 60 in 22 days, which took place all over the country, and often in areas with strong Labour support. Eagle praised him at the time for, “pursuing an itinerary that would make a 25-year-old tired”.

According to Lord Ashcroft’s polling, almost twice as many Labour voters picked Remain over Leave. The only party to have most of its supporters oppose its leader’s view was the Conservatives. Surely David Cameron, Theresa May, or someone else from the team should be blamed for failing to convince their voters before anyone else.

However, the problem with that line of thinking is it ignores how all demographics were split in the referendum. It took support from every age group, political party, region, and economic bracket for Brexit to win.

Nonetheless, Remain did lose, albeit marginally. What followed in print, television, radio, and then across social media, was a repetition that, although he may have tried, Corbyn simply wasn’t active or visible enough during the campaign.

A week before the referendum, I saw Corbyn speak at an event in Birmingham, alongside Neena Gill MEP, Billy Bragg, and Jack Dromey MP. Together, they represented different wings of the Labour party, united by the same message and goal.

Gill was a stiff speaker, but made clear points about what EU funding has done for the city. Bragg was much better, explaining how accountability needed to be central to Labour’s pitch for Remain, as well as his fear of young people not bothering to vote.

Dromey, MP for Birmingham Erdington, and husband to Harriet Harman, began his speech by saying, “Friends, sisters, and brothers I will remain a trade unionist until I die.” This led to loud applause. As did his recounting of times spent on picket lines with Corbyn decades ago. Like Corbyn, Dromey voted against continued membership of the Common Market in 1975 but voted to Remain on Thursday. It was because of this that many were sceptical of Corbyn’s genuine support for the EU. I spoke to a few people that evening who wondered if it was a tactical choice for party unity.

Dromey praised EU victories for human rights, and employment rights, and then went on to condemn Nigel Farage and Boris Johnson’s racism, singling out Farage’s comments on immigrants increasing the chances of rape, and commenting: “How much lower can these bastards sink?”

A child of Irish immigrants, Dromey celebrated the cultural and economic benefits of immigration, and made clear that pressures on public services are the fault of the government, not foreign workers. It was a positive case for EU membership, which was carried on by Corbyn.

Much like during his Sky News interview, Corbyn was undeniably critical of the EU’s flaws, but firm in his support of continued membership in order to reform from within. As George Eaton has said previously, Jeremy Corbyn is not a secret Brexiter. In fact, before his speech in Birmingham, he had spent the day meeting with student nurses to hear about cuts to their bursaries and worries of staff shortages. “A Remain vote isn't a blank cheque,” Jeremy said. “It's a vote to enable us to achieve equality.”

He was well aware of his media absence, expressing frustration that the focus was instead on George Osborne, “who’s trying to crash our economy”, and Boris Johnson, “who’s trying to crash our argument”, and the general Tory infighting, rather than the xenophobia rife in the debate.

His speech went well; his delivery was better than the last time I saw him speak, and he received huge applause when he called out the hollowness of Farage’s argument. "The far right are blaming migrants and minorities. They’re always blaming someone else."

Corbyn portrayed Brexit as, “a race to the bottom economy where the poorest do worst”, and a Remain vote as a route to combatting austerity, the multinationals’ agenda, and climate change. He ended by drawing attention to the 700 refugees in the Mediterranean, who had died that week, as many thousands had before. “They are human beings like us fleeing wars that weren't of their making.”

It went down well, as did his mention of Labour membership having reached 400,000, in addition to 100,000 supporters and 3m affiliated supporters. It made the room feel bigger and the audience more influential. There were easily 500 in the room: far more than the number who turned up to see Gordon Brown a couple of weeks beforehand.

And yet that night, like almost all his other campaign events, went largely unnoticed by those who weren’t there. With the majority of the media distracted, a narrative was created and accepted that Corbyn didn’t do enough. When Brexit won, those who didn’t want Corbyn to be their leader anyway used this as an excuse.

Polling by YouGov estimates as much as 90 per cent of Labour members voted to Remain, which is why painting Corbyn as a secret Leave voter could be integral to his downfall. If believed, it could turn the supporters who elected him against him, allowing a pro-EU challenger to beat him in a leadership election, something unthinkable a month or two ago. But this isn’t about the EU. Look around. The Liberal Democrats are floundering in the polls, often poised to do even worse than in 2015, and their voters were only marginally less divided during the referendum than Labour’s. And yet we don’t seem to hear calls for Tim Farron to step down. This might be because almost no one knows who he is, but that’s largely because Farron is unlikely to be involved in any government this side of 2020. The real concern in the Labour Party is that Corbyn simply isn’t capable of winning a general election.

Theresa May will be Prime Minister before the end of the week. She may have said she opposes a snap election, but I’m reticent to believe her. Any new Prime Minister will want their own mandate, let alone a bigger majority than Cameron scrapped. A fractured Labour Party gives them hope of all this and more.

After imputing various figures into a seat projector on Electoral Calculus’ website, it seems Labour would need around a ten-point lead over the Tories in the next election, in addition to a fall in SNP support, to form a majority government. As it stands, most polls give the Tories a small lead. If these numbers are correct, the best Labour could hope for would be a coalition with at least two partners.

Labour, like most parties, is itself a coalition. Enlarging that further to include parties who oppose trade union rights could be fundamentally unworkable. So it’s no surprise some Labour MPs – so desperate to form a majority government – try changing leaders right as the Tories are in chaos, just in case it somehow gives Labour a bigger electoral boost than even Blair achieved.

Unfortunately for Corbyn, BMG released data last week that stated Labour could receive up to a 12-point increase in the polls if Corbyn weren’t in charge. Based on my previously mentioned electoral projections, this could be enough to deliver that Labour majority government.

That is what fuels this rebellion over Labour party leadership, not Corbyn’s commitment to Remain. If Corbyn is replaced as leader, it won’t be because of the EU referendum any more than Ed Miliband stepped down because of the fall of Scottish Labour. The events that led to Brexit, like the rise of Ukip and the SNP, go back much further than this Labour leader, or even his predecessor. Blaming Corbyn distracts from why so many people felt leaving the EU was a better choice than staying in.

Whether or not there is a change of leadership, the party has to look at why so many voters across all demographics began to leave Labour and back Brexit long before Corbyn became leader. This is because Labour, if it is ever to return to government, will need to find support in every community, and not just those it assumes are default supporters. Ironically, that’s exactly how Brexit won.