Party sources said that the luncheon get-together next Wednesday would facilitate greater interaction with all MPs of the ruling alliance as also supporting parties ahead of the voting.
UPA election managers are confident that alliance candidate Pranab Mukherjee will have a runaway victory in the contest against BJP-backed opposition candidate P A Sangma.
A meeting of the UPA leaders has also been convened here on July 14 ahead of the Presidential poll.
The meeting is expected to take a decision on the issue of Vice Presidential candidate amid signals that a second term for incumbent Hamid Ansari is a possibility.