"The petrol price hike had been withheld for some months ... But the measure will have a cascading effect on the prices of other goods," he told reporters here.
The latest petrol price hike by the state-owned petroleum companies as an ''opportunistic'' step, he said adding now that the elections were over the Centre might also increase the prices of cooking gas and diesel.
Referring to the Congress, Kumar said it had ''hardly gained'' anything in the just-concluded round of assembly elections.
There was nothing to be happy for Congress in West Bengal where the poll result was solely the victory of Trinamool Congress of Mamata Banerjee.
Congress' alliance lost in Tamil Nadu and had to face a keen contest by Kerala Chief Minister V S Achyutananadan, he added.