From 1986 he served as Professor of Political Theory at the University of Essex, where he founded and directed for many years the graduate programme in Ideology and Discourse Analysis, as well as the Centre for Theoretical Studies in the Humanities and the Social Sciences.

Laclau studied history at the University of Buenos Aires[2] and was a member of the PSIN (Socialist Party of the National Left) until 1969, when the British historian Eric Hobsbawm supported his entrance to Oxford.

[3] In the same interview, he claimed that he came from a Yrigoyenista family, and that the Peronist politician Arturo Jauretche, a strong opponent of Justo's dictatorship during the Infamous Decade of the 1930s, was a close friend of his father.

[6][7] Laclau's early work was influenced by Althusserian Marxism and focused on issues debated within Neo-Marxist circles in the 1970s, such as the role of the state, the dynamics of capitalism, the importance of building popular movements, and the possibility of revolution.

In their 2001 introduction to the second edition Laclau and Mouffe commented on this label, stating that whilst 'post-Marxist' they were also 'post-Marxist':[8] their work, though a departure from traditional Western Marxism, retained similar concerns and ideas.

Following several acrimonious publications in the early 2000s, Laclau wrote in On Populist Reason (2005) that Žižek had an impractical and confused approach to politics, describing him as "waiting for the Martians".

[13] Their disagreement escalated in the pages of Critical Inquiry in 2006, when in a spate of essays the two argued in an increasingly hostile manner about political action, Marxism and class struggle, Hegel, populism, and the Lacanian Real.

[14][15] More recently in a 2014 interview with David Howarth, Laclau stated that his relationship with Žižek had deteriorated due to the latter adopting a "frantic ultra-Leftist stance, wrapped in a Leninism of kindergarten".