The Samagi Jana Balawegaya decided to hand over a no-confidence motion against Minister Udaya Gammanpila over the fuel price hike.
The no-confidence motion will carry 10 points gainst Gammanpila who has already come under fire from the SLPP over the price hike.
However, SLPP sources said they were unlikely to support the no-confidence motion against Gammapila despite tensions within the ruling party.
The SJB, led by Opposition Leader Sajith Premadasa, has the support of nearly 50 MPs in the 225-member legislature.