The Black Bull pub on Whitechapel High Street was always a pretty down at heel boozer, standing out as noticeably grubby even in the days when most pubs in that area fairly merited that description. Unsurprisingly, it was turned into an Indian restaurant several years ago, and that’s no great loss to East End drinkers.

But right up until the 1980s, every Thursday night would see a bunch of old boys who had been comrades in the local branch of the Communist Party in its pre-war heyday put back a few beers and chat about the past.

The Smart Alec student Trots in the neighbourhood — among whom I then featured, of course — knew about these drinking sessions, and would affect contempt for the geriatric Stalinist fools. Had they learned nothing in the intervening decades? Would they ever be as all-knowing about Marxist theory as we were?

This was rather ungenerous, of course. After all, when these people were about the same age, they busied themselves fighting the British Union of Fascists on Cable Street and building a working-class base that eventually led to the election of Communist MP. Indeed, the CPGB even hung onto a councillor or two long after that. They cannot have been getting absolutely everything wrong.

What struck me even at that point, though, is that it is possible to speak loosely of generations in leftwing politics. Sometimes they are named after a year, such as the 1956ers or the 1968ers; others coalesce over a slightly longer period, such as the 1930s, or else around specific campaigns, in my case Rock Against Racism and Youth CND.

Naturally they grow old with each other. From time to time I still come across people I worked with in the fight against Thatcherism. They are typically a stone or two heavier and the hair is greying if it hasn’t gone altogether. But a gratifyingly high proportion of them — perhaps almost all of them — are even now interested in politics.

True, only a handful remain paid-up Trots. A fair number have moved to the right, ending up as Blairite councillors or nondescript Green Party members or respectable union officials. They tend to be somewhat embarrassed at any recollections of those early morning factory gate paper sales after those all-night Hackney squat parties.

Yet many of the others have hung on to at least a part of their youthful ideals. It’s just that parental responsibilities and healthcare worries make activism harder, while disgust at the lows that Blair inflicted on the Labour Party and the continuing stupidities of the far left have reinforced the cynicism that comes naturally with middle age. But to this day they see themselves as socialists, and maybe even revolutionary socialists.

The trouble is, the left’s last sizeable ‘generation’ intake probably came with the miners’ strike, which is now a long, long time ago. Don’t get me wrong; many good individuals radicalised around later issues, such as the poll tax or the invasion of Iraq, and got involved with Marxist organisations.

But the numbers have not been sufficient to meet the qualifying threshold I’m talking about here. For many years, the proof of that proposition could be ascertained simply by looking round the room during a leftwing meeting. The absence of anyone under about 40 was all too noticeable.

That finally appears to be changing. At the two meetings I attended in the week prior to writing this, more than half the room were not old enough to regularly require moisturising cream.

The reason is obvious, I guess. The student demonstrations in recent months, followed by the wave of uprisings in north Africa, are generating an enthusiasm for activism on a scale that has been conspicuously lacking since the last time I looked good in leather trousers.

Friends who are in Trot groups tell me that they are recruiting some of these people, and from the tone in their voice, it is obvious that this time they are not lying.

The question is whether there will be enough newcomers to constitute a ‘2010 generation’, a development that would do a power of good to a milieu that has in some cases become as sclerotic in its politics as it has unfortunately sometimes become in its arteries. I can only wish them greater success than we had.