Arun Shourie is pushing for rapid sell-offs

According to unions, as many as 30,000 workers took part in the strike at Hindustan Petroleum and Bharat Petroleum, with another 7,000 or so management staff deciding to keep working.

"This strike is a warning to the government that it should reverse its earlier decision to sell off the stakes in these oil companies," Swadesh Debroy, National Secretary of the Centre of Indian Trade Unions, told the BBC.

Production at some refineries was down to 50% as a result of the strike, he said.

The two companies, which between them control 40% of India's domestic oil products market, are in line for privatisation which has been long-delayed by political opposition from within the cabinet.

But observers said the strikes stood little chance of derailing the privatisation process now the hand of Disinvestment Minister Arun Shourie has been strengthened in the latest cabinet reshuffle.

Back on track?

India's disinvestment programme has been stuck in the mud for months, missing its targets for four successive years thanks to vociferous protests from, among others, the hardline Hindu nationalist wing of the government.

For some on the more radical fringe of the government, the plan to float 35% of Bharat on the market and sell 36% of Hindustan to a single investor is tantamount to selling-off national treasures.

Both companies are profitable, and some hardliners say the government should get rid of loss-making companies which need foreign assistance first.

Others, such as Defence Minister George Fernandes, have argued that there are strategic and national security imperatives to consider before putting influence over India's energy industry in foreign hands.