There’s a dramatic day ahead in the Labour leadership contest, with the first stage of the process closing this afternoon. The candidates must have secured the nominations of at least 22 MPs or MEPs by 2.30pm in order to proceed to the next step. And while Keir Starmer, Rebecca Long-Bailey, Jess Phillips and Lisa Nandy have all passed that threshold, Emily Thornberry and Clive Lewis are desperately trying to persuade colleagues to back them in the next few hours.

Thornberry seems more confident than Lewis that she’ll make it. She has 10 nominations so far, while Lewis has just four, and there is a campaign from Labour women to get Thornberry over the line in order to ensure a greater diversity in the contest (presumably because it’s important to have two North London lawyers who insist they are working class despite everyone accusing them of being posh).

Thornberry’s pitch is that she already knows how to stand up to Boris Johnson, as she did it while shadowing him in the Foreign Office. Her frontbench performances are known for being fierce and incisive, and she often showed up Jeremy Corbyn when deputising for him at Prime Minister’s Questions. So why is she doing so badly?

Yesterday’s Marr interview offered us one clue. Thornberry was shown a tweet she sent back in 2014 which still haunts her: the ‘Image from Rochester’ which got her sacked. Despite her insisting that she wasn’t mocking patriotic working-class voters, Thornberry continues to be haunted by this post many years later, partly because her colleagues suspect that she does have a snooty attitude to such people. One of her frontbench colleagues is more sympathetic: ‘this idea has slightly taken hold that we need someone who can connect with the North and there is a sense that she exemplifies North London metropolitanism. It’s unfair on her personally as I think her background is more complex than that and it feels to me that Keir gets away with it more because of latent sexism.’

But one of the reasons that Rochester tweet was potent enough to cost Thornberry her job on Ed Miliband’s frontbench is that she is not popular in the party. There were not enough MPs prepared to go out and defend her; in fact, there were more who were quite keen to throw her under the bus at the time. It seems that the situation hasn’t sufficiently improved now, as not enough MPs have been prepared to back her early on. She has a reputation for treating those she considers unimportant to her with rather less respect than they’d hope. This matters to everyone, but especially to MPs. When I asked one of her colleagues why her campaign was struggling, he replied: 'One of the strengths of MPs being involved in the nomination and one of the reasons that MPs in the past have had a decisive voice in the leadership elections is that MPs tend to know their colleagues best.' That's not, in case you were reading too fast, a compliment.

If she does make it to 22 by this afternoon, Thornberry will join the other candidates in trying to get the support of at least 33 constituency Labour parties or three affiliated organisations. The focus of the campaign will switch to the membership and away from the parliamentary colleagues that Thornberry has struggled with. Given the relationship between Jeremy Corbyn and the parliamentary party over the past few years, it’s not clear whether the membership sees being unpopular with MPs as a bonus or a disadvantage. If Thornberry does make it through, we could be about to find out.