India's Congress Party President and leader of United Progressive Alliance Sonia Gandhi discussed government formation with President A P J Abdul Kalam on Tuesday.

Emerging from a 20-minute meeting in the presidential palace, Sonia Gandhi told reporters she would meet the president again on Wednesday, with letters of support from all coalition partners.

"We were called for preliminary discussion on formation of government. The President was keen to know about the parties, which are supporting us from outside and those who are supporting us from inside, which means pre-poll allies," Sonia said.

"We explained to him these issues. Again, we shall meet the President tomorrow, with letters of support from all coalition partners," Gandhi added.

Gandhi, who was accompanied by senior Congress leader Manmohan Singh, said, "At the moment, the left parties are not participating in the government and will support it from outside."

When asked about the swearing-in ceremony, Gandhi said, "You will see it very soon."

Gandhi's meeting followed an invitation from the President on Tuesday, for discussions on formation of new government.