(BS) : Centre plans to implement labour codes on April 1. Industries will have to file a single return to the authorities under the new labour law regime. As many as 29 labour laws have been converted into four codes. The codes got the approval of Parliament during the monsoon session when the Opposition organised a boycott to oppose the farm Bills. government has brought about key changes to the labour laws. These include easier retrenchment norms, flexibility in hiring contract workers, equal social security benefits for fixedterm and permanent staff, social security cover for gig and migrant workers, and relaxation to smaller factories from labour laws.