I’ve spent more than enough time with lefties over the years to get to know the implacable ones and the rest. By which I mean the ones who are democratic, fundamentally, and the ones who fondly imagine themselves to be revolutionary, either as Trotskyists, Stalinists, or Maoist or something else. The revolutionaries, the likes of Militant in Labour’s past, support violent struggle.

From what I have seen of Momentum, including immersion at their first conference, their dedication to peace and democracy – or at least their take on it – means they are susceptible to debate, the lessons of experience and rational thought. The younger Momentum members especially lack that searing emotional response to losing four general elections in a row and living a good chunk of their lives under Thatcher and Major. Or even Blair, some are so youthful.

For them, politics began in 2015 with Jeremy Corbyn, and everything is possible. And yet they’re interested in what happened before, and how and why New Labour was invented. They may think Blair ought to be packed off to The Hague for war crimes but they are not mad enough to think he arrived as part of some establishment plot.

Unlike Militant, they do want to win elections and campaign on the streets. Evidently they’re much less keen on turning up to Labour meetings and sitting on dull committees or standing as candidates and taking over the bureaucratic Labour machine, again in stark contrast to the Trots. The Momentum lot, in other words, are a bit more normal, though I’d not exaggerate things.

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What was missing at the Momentum conference was the presence of MPs, particularly from the Labour centre or Blairite wing. Liz Kendall or Stephen Kinnock or Chuka Umunna could have sat on a platform and debated with, say, Jon Lansman and an audience of the confused and naive. It would have been unpleasant but the party dialogue would have started, and the discussion that ended with the doomed candidacy of Owen Smith for the leadership been revived, as it will surely have to be. Why wait?

Without sounding patronising, there are two ways for the folk in Momentum to become part of a governing party that at least does some good for the people they genuinely care about. The first is to lose four general elections in a row: the slow learner route. So that would be 2010, 2015, 2020 and 2025, say, with some new version of Blair getting into Downing Street after the Tories are naturally exhausted in about 2030. By which point, lots of the young activists wearing Docs and badges will be Labour MPs, fed up with waiting around and far to the right of where they are now, in smart business clothing. That was, in fact, how the likes of Peter Mandelson, Robin Cook and David Blunkett wound up in the cabinet, all far left in their day.

Or Momentum can be argued with, taught, persuaded, even convinced that they need to change long before all that damage is done, before it is too late. That was never possible with Militant, who rejected parliamentary democracy. Momentum is not so doctrinaire.

Frankly few would be convinced, I know, but my point is that dialogue has to start now. Momentum love an argument and the social democrats in Labour aren’t giving them one right now. If I were Liz or Chuka, I’d have been on the first train to the Momentum conference in Birmingham to start the process of Labour renewal before it is too unsalvageable. If Momentum wouldn’t let me in, I’d hire somewhere in Birmingham and invite Momentum to turn up and try to win the arguments.

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Labour MPs look defeated and resigned to the wilderness. Well , if they stop fighting, then they will indeed spend the rest of their political lives in opposition because there’s always an excuse for a quiet life. They’ll be drawing their pensions and retired by the time the Tories leave office.