Alex Wickham

When Paul Mason was covertly recorded by the Sun newspaper divulging his private view that Jeremy Corbyn does not appeal to the working classes, there wasn’t much surprise in the Labour leader’s office. The relationship between Corbyn and his celebrity guru has always been complex. Kremlinologists point to a meeting of Corbyn’s closest comrades earlier this year at Esher Place, a £6 million, Grade II country house in Surrey owned by Unite. The guest list was a who’s who of the hard left: John McDonnell, Diane Abbott, Len McCluskey, Labour strategy chief Seumas Milne and Momentum boss Jon Lansman were all in attendance. Corbyn had also invited Mason to join this star chamber.

If there is one word that strikes fear and loathing into the hearts of Labour MPs, it is Momentum. This mixed bag of Trots, tankies, cranks and hipsters who delivered Jeremy Corbyn the leadership has become his Red Guards. Its name is synonymous with the new wave of hard-left entryism into Labour, calls to deselect moderate MPs, picketing offices, harassing staff and tweeting bile. So it doesn’t quite fit the public persona that its founder and chief commissar, Jon Lansman, is such an affable fellow. The 59-year-old Lansman is full of contradictions. He is the leader of Britain’s most notorious and divisive political movement, yet Labour colleagues agree he is ‘a lovely man’, ‘a loveable rogue’.

My phone vibrates with a three-letter text message heralding another inevitable Westminster hangover: “MoG?”. The Marquis of Granby pub on Romney Street is an old-fashioned sort of boozer: mahogany-panelled bar with a chandeliered burgundy ceiling and a gents you have to wade through. There’s none of your poncey hipster food served on slabs of wood here; if you head to the upstairs dining room you’re having a pie and a pint. You can see why Nigel Farage loves this place for a photo opportunity. I’m meeting another journalist for an ale and a gossip, but this used to be a Tory haunt before Conservative Central Office moved from Smith Square.

In February, a member of John McDonnell’s team accidentally forwarded his diary to a Labour party colleague. The errant email has been a source of gossip among Corbynistas ever since. Among the mundane schedule of meetings were a series of slots allocated for something rather out of the ordinary: ‘Transition planning.’ McDonnell’s aides swear up and down that these meetings are nothing untoward and warn against ‘putting two and two together and coming up with a million’. But the fact that it even raised eyebrows is telling.

Standing on chairs in Parliament’s Sports and Social bar, a band of portly gentlemen are bellowing out Scottish folk songs. A young barmaid, only in her early twenties yet a seasoned veteran when it comes to turfing out unruly Westminster soaks, approaches a new SNP MP and politely asks him to pack it in. Words are exchanged. Multiple witnesses allege a drunken ‘f— you’ is uttered. Defeated, the barmaid retreats behind the bar to mocking male laughter. So upset is she by the incident, she will leave her job a few weeks later. ‘They’re only just getting started,’ sighs a Labour wag as he reaches for his coat. The conquering horde of Scots Nats have come to town and they are making themselves heard.