The two decades that followed the Second Reform Act represent a critical period in the prehistory of the Labour party. Throughout this period the labour movement constantly re-evaluated the state of its relationship with official Liberalism. The franchise revolution of 1867 and the subsequent changes in local party organisation raised serious questions not only for a labour movement seeking to secure political representation, but also for a Liberal party that had to respond to the pressures of mass politics. With Gladstone's first government tackling a range of issues that directly affected the lives of the labouring classes, not least trade union legislation, the labour movement felt it was essential to have working-class men, with expert knowledge on these issues, returned to Parliament. This was the rationale behind the formation of the Labour Representation League (LRL) in 1869. There can be little doubt that the LRL wished its candidates to be elected as Liberal MPs who would directly represent the labour interest. From the outset, the LRL identified the national Liberal party as the best vehicle to promote its interests. The problem was that in order to be successful, its candidates needed to be selected by a local Liberal association and brought forward as the official Liberal candidate. Labour's interactions with the caucus were therefore pivotal in determining how the movement conceptualised its identity in relation to official Liberalism.

The era of mass politics ushered in by the Second Reform Act created new challenges for the two main political parties in the sphere of electoral politics. Amidst concerns about the effects of popular pressure, both the Liberal and Conservative parties faced the difficult task of balancing the demands of the various interest groups within them. In addition to dissent and the temperance interest, the Liberal party recognised the need to reach out to the labour movement. The Howell-Glyn pact of 1868 reflected the desire of the Liberal leadership to introduce new electoral machinery to bring working-class political activists within the Liberal fold, but as a method of securing an electoral alliance between the labour movement and the Liberal party it was unsustainable. The passing of the Criminal Law Amendment Act in 1871 made it clear to the leaders of the LRL that working men were needed in Parliament; simply joining local Liberal associations was not enough.