Attacking the government for "striking another blow" to the ''aam admi'', they said the hikes come at a time "when the people are suffering from all round price rise and the inflation rate has crossed nine per cent".
Asking all their units to immediately conduct hartals, demonstrations and other protest actions, the CPI(M), CPI, RSP and Forward Bloc said it was "another cruel blow" to the common people as the increase in diesel price would raise the transportation cost and affect farmers, while those in kerosene and LPG cylinders would burden the poor.
In a joint statement, the parties said the withdrawal of five percentage points in customs duty on crude oil, imposed last year, "shows how such taxes are levied by the Centre to raise revenue and this is the main cause for the high prices of petroleum products".
"Yet, the government refuses to restructure the taxes on petroleum products and give up the ad valorem tax", the four Left parties said, demanding that the hike be withdrawn immediately.
The statement was signed by CPI(M) General Secretary Prakash Karat, CPI's A B Bardhan, RSP's T J Chandrachoodan and Forward Bloc''s Debabrata Biswas.
Earlier, CPI National Secretary D Raja accused the government of kneeling down before market forces and corporate houses and demanded immediate roll back of prices.
Observing that the move came immediately after the assembly polls, he said, "There is no transparency in the oil sector. No one knows what the spot price of crude is, the cost of refining it and the real component of taxes."
Accusing the government of allowing corporate houses to plunder indigenous resources like natural gas, he said this has been recently exposed by the Kaveri-Godavari basin gas scandal.
"The Supreme Court has said that natural gases are national assets. How does the government gives this national asset on a platter to corporate houses.
CPI(M) leader Sitaram Yechury yesterday termed the hikes "completely unacceptable" and said "Government had committed to zero duty on petroleum products when it deregulated their prices. It has not stuck to its promise. Instead, it is imposing a burden on the people."