"I seek your kind attention on securing additional supply of coal for the National Aluminium Company [Get Quote]. I request you to instruct concerned authorities to provide additional coal to the PSU at the earliest," mines minister Sis Ram Ola said in a letter to Singh.

He pointed out that the Navratna company is currently implementing its expansion plans and it was imperative to ensure adequate coal for its captive power plants in Orissa.

Ola also drew Railway Minister Lalu Prasad's attention to the fact that shortage of rakes was crippling coal supply to Nalco's smelter and suggested that additional rakes be made available to enable the PSU to ferry coal from the pithead to the power plants.

A NALCO spokesman told PTI that the company has already closed down two of its captive plants owing to critical coal stock position. "We need about 15,000 tons of coal everyday, while we are getting only 8000 to 9000 tons," he said.

Orissa chief minister Naveen Patnaik too has written to the Prime Minister stating that the shortage of coal would adversely affect the company's production and requested the Prime Minister to direct Mahanadi Coalfields Limited to ensure that Nalco's coal requirement was met.

Nalco CMD C R Pradhan in his letter to Ola said, "Unless Railways help us immediately by allotting one-and-a-half rakes per day we have no other option than to close one of our three operating potlines in the smelter plant."