This paper examines how the empire’s hysteria against militant trade unionism and its anti-colonial essence lay at the root of the colonial state’s proliferation of surveillance apparatus in late colonial Bengal. It primarily focuses on how the state censored, proscribed, and surveilled the literary output of trade unionists and other working-class propaganda materials to establish that it was a systematic effort to curb indigenous anti-colonial epistemologies. The article explores the legal provisions implemented to constrain the import, production, and dissemination of these materials as an ideological onslaught against the growing threat from militant and leftist nationalism. Through a thorough review of newspapers, proscribed journals, pamphlets, banners, and slogans produced between 1920 and 1940 within the urban working-class movement of Calcutta, this paper highlights how surveillance transcended being a mere tool of colonial oppression and became an integral part of the empire’s political rhetoric in the subcontinent. The study further evaluates the varying scales of spatiality in imperial surveillance and its policies to comprehend the transforming nature of governance and ordering in the closing decades of British rule in India.