In 1907–1908, the British labour leader, James Keir Hardie, made a round-the-world tour, which included visits to India, Australasia and southern Africa. The support for Indian nationalism which he expressed precipitated a major international political controversy, in the course of which Hardie came under severe attack from the Right, both in Britain and in her colonies. In southern Africa, the issue, combined with Hardie’s earlier criticism of the repression of the 1906 Bambatha rising in Natal, sparked rioting against Hardie by British settlers during his visit. This article seeks to show how Hardie’s voyage illuminates the imperial politics of its moment. Hardie’s journey demonstrates how politics in the British colonies of his era took place not within local political boundaries, but in a single field which covered both metropolis and colonies. The article is a case study which helps to illustrate and develop an argument that the white working classes in the pre-First World War British Empire were not composed of nationally discrete entities, but were bound together into an imperial working class which developed a distinct common ideology, White Labourism, fusing elements of racism and xenophobia with worker militancy and anti-capitalism. The current paper refines this analysis of the politics of the imperial working class by situating it in relation to the rising force of Indian nationalism in the same period, and to the changes this development generated in the politics of the settler colonies and the imperial centre. In India, Hardie forged links with the dynamic new political mobilization that had followed on the crisis over the partition of Bengal. In doing so, he entered, as an ally, into the discursive struggle which Indian nationalists were waging for self-government. By taking a pro-Indian position he antagonized the British Right. Labourites in the white settlement colonies wanted to defend Hardie, as a representative figure of British labour, but were embarrassed by the fact that Hardie’s position on India went against the grain of White Labourist ideology. In southern Africa, local leaders of British labour did opt to defend Hardie. But they did so not only at the risk of alienating their members, but also at the price of being forced into direct confrontations with anti-Hardie groupings.