Prime minister Manmohan Singh will soon write to the MPs and MLAs to set an example as people's representatives by forgoing subsidy on liquefied petroleum gas (LPG or the cooking gas), and pay for the cylinders at the commercial rate.

The petroleum ministry expects that this would encourage the rich and affluent also to voluntarily give up the subsidised LPG, instead of the government raising the price to keep its subsidy bill under check, minister of state RPN Singh said on Monday.

The LPG is a controlled commodity and the government is subsidising the oil companies to the tune of Rs 25,000 crore to keep its price for the domestic consumers low at around Rs 400 a cylinder as against the actual price hovering around Rs 1,200 a cylinder.

Singh hopes that the voluntary action of those who can afford to pay the actual price would help the government to keep the LPG price low for the rest.

The voluntary scheme is being proposed as an alternative to a proposal pending with the government to withdraw the LPG subsidy in two phases, first to members of parliament, legislatures and all gazetted officers and second to all families earning more than Rs 50,000 a month.