Kelman's work has been described as flowing "not only from being an
engaged writer, but a cultural and political activist". At the time of Glasgow's Year as City of Culture he was prominent in the Workers' City group, critical of the celebrations. The name was chosen as to draw attention to the renaming of part of the city centre as the Merchant City, which they described as promoting the "fallacy that Glasgow somehow exists because of (...) 18th century entrepreneurs and far-sighted politicians. (The merchants) were men who trafficked in degradation, causing untold misery, death and starvation to thousands" The Workers' City group campaigned against what was seen as the victimisation of People's Palace curator Elspeth King and a Council attempt to sell off one third of Glasgow Green. Their activities drew the ire of Labour Party councillors and commentators, Kelman, and his colleagues Hugh Savage and Farquhar McLay, being described as "an 'embarrassment' to the city's 'cultural workforce'".
Kelman has been a prominent campaigner, notably in issues of social justice and traditional left wing causes, although he is resolutely not a party man, and remains at his heart a libertarian socialist anarchist, saying "the parliamentary opposition parties are essential to the political apparatus of this country which is designed to arrest justice". He lives in Glasgow with his wife and children, though has also lived in London, Manchester, the Channel Islands, Australia and America.
In his introduction to
Born up a Close: memoirs of a Brigton boy (2006), an edition of Glaswegian political campaigner Hugh Savage's writings, Kelman sums up his understanding of the history of national and class conflict as follows:
In an occupied country indigenous history can only be radical. It is a class issue. The intellectual life of working class people is ‘occupied’. In a colonised country intellectual occupation takes place throughout society. The closer to the ruling class we get the less difference there exists in language and culture, until finally we find that questions fundamental to society at its widest level are settled by members of the same closely knit circle, occasionally even the same family or ‘bloodline’. And the outcome of that can be war, the slaughter of working class people.