Some Irish migrants engaged with revolutionary left politics in Britain. Especially during the 1970s and 1980s, these radical migrants campaigned against British rule in Ireland. The Prisoners Aid Committee was a prominent campaign group on the British left in the 1970s. They exhorted British workers, and especially those in trades unions, to oppose the British government’s rule in Northern Ireland and to support the ‘Irish people’s right to self-determination’.

But relations between British leftists and Irish republicans were often fraught. Organisational rivalries on the British left frustrated activists who aspired to building a mass campaign for Irish unification. For example, a Prisoners Aid Committee activist in Liverpool wrote exasperatedly in 1974: ‘If the Irish in England can’t agree to work together, how can we expect support from our British Comrades?’