The petroleum ministry's decision to hike the price of natural gas was taken under Reliance Industries Ltd's coercion, CPI MP Gurudas Dasgupta has alleged.

Mr. Dasgupta described the move as a "gigantic scam" in the making and stressed that Prime Minister Manmohan Singh should intervene in the matter at the earliest.

The senior Left leader said, "This is a gigantic scam that is in the process of being enacted through the generous assistance of the petroleum ministry, a national loot of the country's natural resources."

Mr. Dasgupta accused Petroleum Minister M Veerappa Moily of offering undue assistance to Reliance Industries by recommending a higher price for natural gas than that suggested by the Rangarajan Committee.

He also claimed that secretary to the petroleum ministry had thrice opposed the petroleum minister's decision on natural gas pricing, but the minister still overruled the secretary's opinion.

He claimed that there was exchange of information between Moily and Reliance Industries, and demanded the dismissal of the petroleum minister.

Mr. Dasgupta also stressed that this would be the biggest scam if it was allowed to take place in the tenure of UPA-II.