'This is a trigger warning for working class people,' says Darren McGarvey, otherwise known as Loki, 'they're selling juice with bits at the bar.' Yet the rapper from Pollok in Glasgow, working class himself, seems firmly in his comfort zone here, performing to a large audience of mixed age and sex. They may or may not have been getting what they expected – given that his star has risen significantly in the last few months thanks to the success of his Orwell Prize-winning memoir Poverty Safari and his reinvention as a cultural commentator of straight-talking insight and accuracy – but they were certainly getting what they needed.

Poverty Safari Live is a rap and spoken word show telling the story of a working class Glasgow boy with a middle class girlfriend at university, and the alienation and threat he feels in her world. Yet between the margins it's also a piece of first-person polemic from McGarvey himself, who notes wryly that he has to annotate his character's blunt edges – particularly the homophobia – in a way middle class writers don't have to ('I'm a rapper, so no sophistication is assumed').

He rails again the notion of social mobility being possible from a position of extreme poverty (the idea is 'the gentrification of class consciousness … I prefer to talk about social immobility'), confronts the difficulty he initially experienced in coming to terms with contemporary feminism, and – not forgetting we're at the Stand – makes it all darkly funny; 'I'm invisible to London … I'm Warrington in human form.' The voice McGarvey has found for himself is one for our times, and sorely needed; uncompromising in his quest for basic decency across class borders, but humble enough to know that our opinions should fluctuate in the face of others' lived experience. Before you see any knowing political shows by men in expensive suits this year, see this one instead.

The Stand's New Town Theatre, until 26 Aug (not 15), 5pm, £12 (£10).