The Supreme Court held that while the Central Government has the power to provide for the grant of post-facto environmental clearances (ECs) through valid statutory notifications issued under Section 3 of the Environment (Protection) Act, 1986, it cannot do so through a mere administrative office memorandum.

https://www.livelaw.in/top-stories/supreme-court-says-centre-can-allow-post-facto-environmental-clearances-through-statutory-notification-quashes-2021-office-memorandum-543346