The Congress on Wednesday accused the Centre of misleading the public and pushing through a “fatally flawed” redefinition of the Aravalli hills, despite objections from key expert bodies and advisers to the Supreme Court.

Congress general secretary Jairam Ramesh said the revised definition had been opposed by the Forest Survey of India, the Supreme Court–appointed Central Empowered Committee, and the court’s amicus curiae.

Under the new criteria, an Aravalli Hill is defined as a landform rising at least 100 metres above the surrounding terrain, while an Aravalli Range is a cluster of two or more such hills within 500 metres of each other.

Critics argue that this excludes several ecologically vital components of the Aravalli system, such as low ridges, slopes, foothills and groundwater recharge zones that may not meet the 100-metre threshold but play a crucial role in biodiversity, climate regulation, soil stability and water security.

The Centre has denied that the redefinition dilutes environmental safeguards, maintaining that over 90 per cent of the Aravalli region remains protected and that mining controls are unchanged.

However, Ramesh alleged that the Environment Ministry was “being economical with the truth” and questioned why the Modi government was persisting with a redefinition opposed by expert institutions.

The Congress has earlier said the Aravallis are a national natural heritage and warned that redefining them could undermine their ecological protection.