The UNP has opened up a dialogue with 17 SLFP MPs to draw their support for the budget proposals in April, informed political sources said.
The SLFP currently has 21 MPs in the House as other MPs representing the UPFA coalition have pledged their support to the Sri Lanka Podujana Party (SLPP).
Finance and Media Minister Mangala Samaraweera will deliver the budget speech to Parliament during the first week of April.
However, President Maithripala Sirisena has refused to give ministerial and deputy ministerial positions to SLFP MPs who have crossed over to the government.
"They don't demand positions. They will only work with the government for a certain period. They will continue to remain SLFPers," a senior UNP spokesman told Asian Mirror.
Several SLFP Parliamentarians, including Vijith Vijayamuni Zoysa, Piyasena Gamage, A.H.M. Fowzie, Lakshman Seneviratne and Indika Badaranaike have already joined the UNP-led government.