"nnowadays it has to encompass a large (and growing) sector of people who are either precariously (under)employed, or who are not employed at all" wow, that is unusual for British capitalism. lol are you one of these underclass merchants?
and hasn't always the working class had heterogeneous interests? Why more so today?
He's actually making a perfectly valid point (though one I'm not sure I completely agree with, need to have a think about it) since, for Thompson, class was an historical phenomenon - rather than being defined by the relations of production, it's merely partially determined by it. Class only "happens" when workers act as a class, or "act in class ways" as Thompson would put it. It's a combination of objective and subjective factors, or to use Marxist jargon, class only happens when class consciousness happens.
And the thing about them always having had hetrogenous interests - when Thompson was writing the labour movement was strong. We had large, unionised workplaces. In other words it was accurate to talk of a working class, who had seperate interests from the rest of society and, most importantly, were conscious of this fact and acted accordingly. And during the period he was writing about this was even more the case.
The reason I'm not sure if I agree is that there is still a relatively significant minority of workers who are well organised, view themselves as a class apart and their interests as intertwined with those of other workers, and since these workers operate in just about every sector of the economy I'm not sure you can separate the various working classes, or at least it's not as simple as that. But maybe I'm just stretching it a bit because it suits my prejudices, which is why I need to think about it.
See how I've engaged with what he actually said there? When you do that people will accept disagreement. It's the disrespectful and dishonest way you represent the views of others that pisses people off, not the fact that they disagree with you.
And just because the SWP say they want unity, that they want, as you so frequently state, the self-emancipation of the working class, that doesn't mean that they do so in reality. We judge political actors by their actions, not their words. Do you believe that David Cameron really wants what's in the interests of the population of the UK? That the Tories don't want to privatise the NHS? That the Lib Dems and New Labour are progressive and want a more equal society? Of course we don't. So why do you leave your scepticism at the door when it comes to the SWP? And just for the record, I don't believe you when you say you're no longer in the SWP. Your posts on here only make sense if we assume you're still a member, or at least still believe they're the one true faith.