India's environment ministry has allowed coal mines with clearances to increase output by 40% to step up production by up to 50% without seeking feedback from locals, it said in a memo reviewed by Reuters.

The decision was taken after a request from the coal ministry which pointed to "huge pressure on domestic coal supply in the country," the ministry said in a memo dated May 7, adding that the "special dispensation" will be valid for six months.

India is also planning to reopen more than 100 coal mines previously considered financially unsustainable, as the worst power crisis in over six years driven by a scorching heatwave forces the world's third-biggest greenhouse gas emitter to double down on the fuel after months of low consumption.

The projects "shall be granted expansion environmental clearance to increase their production capacity to 50% of original capacity within the same mine lease area without requiring revised environmental impact assessment report for additional capacity and public consultation," the memo read.

Demand for coal has risen due to post-pandemic economic recovery and an unrelenting heatwave. The government is forcing utilities to step up imports and Coal India to ramp up production to address supply shortages.

India, the world's second-largest producer, importer and consumer of coal behind China, addresses nearly 75% of its electricity requirement using coal.

(Reporting by Sudarshan Varadhan; Editing by Stephen Coates)