We can't help but think that this is a horrible mistake:

T-shirts sold to raise money for Jeremy Corbyn’s Labour leadership campaign are being made by poverty-stricken workers earning just 30p an hour, The Mail on Sunday can reveal.

The machinists in Bangladesh toil for up to ten hours a day to make the garments, which are believed to have raised thousands of pounds for the Labour leader’s fighting fund.

...
Yet a Mail on Sunday investigation has discovered that Momentum – the Left-wing organisation central to Corbyn’s leadership campaign – has bought hundreds of the T-shirts, some emblazoned with the politician’s name in superhero-style lettering, to sell here for £10 each.
 

No, not that, that's eminently sensible. If you're trying to raise money for something then you want to be cutting your input costs to the bone. No, this is the mistake:

Last night Momentum cancelled its contract with the British supplier of the T-shirts and promised to ‘rigorously’ check the sourcing of its merchandise in the future.

Why cancel? Providing work for the labouring man to do is a good thing, surely? And as Madsen Pirie of this parish has been saying for at least a decade so far - buying things made by poor people in poor countries makes those poor people richer.

Thus what better manner to advance the cause of international brotherhood? Something which we believe is the sort of thing Momentum peeps mouth off about.

The poor worker gets 30p a t-shirt. around 25 p more than they would make in the same time staring at the south end of a north moving water buffalo. £9.70 is raised for Jezza's campaign.

International trade and voluntary exchange make all better off. So why not do more of it?

Yes, we think it must just be a horrible mistake. For surely they're not so ignorant as to believe that voluntary exchange and international trade don't make everyone better off, are they?