The Left parties will have a separate meeting followed by those with other secular parties, while the BJP and its allies will hold separate talks to decide how to go about to press their common cause.
Leaders like RJD chief Lalu Prasad and SP chief Mulayam Singh Yadav have declared that the entire opposition was together on the demand for rollback and would not allow Parliament to function till the demand was met.
The parleys between opposition leaders assume significance against the backdrop of Prime Minister Manmohan Singh ruling out any rollback, saying the economy has the capacity to absorb the increase without triggering inflationary pressure.
Incidentally, RJD, SP and BSP, opposing the hike are outside supporters of the ruling UPA without whose 47-member strong prop the Congress-led coalition could be walking on thin ice if the issue precipitates.
However, Trinamool Congress chief Mamata Banerjee, whose party is also seeking a rollback like the DMK, has raised the comfort level of the government.
Banerjee has scotched rumours that the sharp criticism of the price hike by her party has caused unease in the alliance with Congress and said the coalition would continue "despite obstacles".
Roll back petro price: Mamata urges PM, Sonia
PM appeals to Oppn not to disrupt Parliament
When Mamata Banerjee was almost reduced to tears
BJP mulls disciplinary action against Raje
Lalu elected RJD chief for seventh time