The labour unions of state-run Coal India Ltd have threatened to go on a five-day strike beginning January 6 to protest government plans to sell off a stake and end the company's monopoly in mining and distribution, officials said.
The call for the strike exacerbates concerns about supplies from Coal India, the world's biggest coal miner which accounts for about 80% of country's output. The country uses coal to generate more than half of its electricity.
The firm often falls short of its output targets due to strikes, delays in getting permissions to expand mines and other bureaucratic hurdles, forcing India to import coal despite the fact that it is home to the world's fifth-largest coal reserve.
Five labour unions, including the one affiliated to BJP, have planned a five-day strike from January 6, said Jibon Roy, general secretary of the All India Coal Workers Federation.
Workers will also go on a separate strike on January 13 to press for better working conditions, including a five-day week with 35 hours of work, Roy said.
Last month, Coal India trade unions called off a planned strike in a move that seemed to set the stage for Modi to press ahead with energy reforms.
The government wants to sell the Coal India stake to meet its $9.5 billion annual divestment target. The move will help India trim its fiscal deficit.
The government in 2010 sold a 10% stake in Coal India, raising $3.4 billion in an initial public offer.