One issue particularly impacted on Thevar's political career. The Criminal Tribes Act (CTA) had been enacted in 1920 by the government of the Madras Presidency and was subsequently implemented in a piecemeal fashion. Thevar mobilised resistance to it, touring villages in the affected areas and leading protest rallies for the rights of the individuals registered under it. In 1929, the Maravars of 19 villages in Appanad were forced to register, under the CTA. Thevar led a massive campaign in the villages, urging the people to defy it. The authorities partially withdrew, and reduced the number of CTA registrations in the concerned areas from around 2000 to 341.