The Centre should immediately instruct the oil companies to release unleaded petrol and diesel to the bunks, she said.
"Prices of branded petrol and diesel are being fixed by the companies themselves as the Centre does not prescribe the prices for these commodities. The companies have the freedom to fix their prices, leaving scope for unauthorised hike in petroleum products prices," she said in a statement.
If such a situation continues prices of petroleum products would continue to increase, affecting the poor and middle class as prices of other commodities would go up, she said.
Charging the Tamil Nadu government with being a mute spectator to the situation, she said it was because the state thought that the loss of revenue due to reduction of two per cent sales tax on diesel could be "compensated by this."
When people were demanding a rollback in prices of petroleum products, the oil companies were jacking up the prices by selling only branded petrol and diesel, she added.