Finance Minister Pranab Mukherjee on Saturday said the two most vexed issues facing the nation are price rise in essential commodities and petro-products.Mr. Mukherjee told a Congress seminar in Behrampore in West Bengal that is not possible for the Centre to decrease the price of petro-products because huge subsidies are already beinggiven to the oil companies for sale of fuel at controlled rates. He said, crude is being imported at a price many times more than at the time of the Budget. Mukherjee said foreign oil firms were also increasing the prices of petro-products.State governments, he said, cannot continue to rely on loans from the Centre and have to increase their own sources of revenue to tackle the situation.Suggesting a way to tackle inflation in essential commodities, he said the PDS system should be strengthened. He said, a strong PDS system will benefit 40 crore people and help arrest the price spiral.