The Centre for Sciences and Environment (CSE) claimed in a study that the government's plans to introduce these cars without ensuring sufficiently stringent emission and safety standards would create environmental problems.

"Even though these small cars are expected to be more fuel-efficient than bigger cars and SUVs, their sheer numbers will undercut the fuel savings possible from the more fuel- efficient two-wheelers and the energy sufficiency possible from public transport," a CSE release said.

The study also suggested that the government must guard against permitting these cars to run on diesel.