The Congress-led United Progressive Alliance (UPA), which emerged the largest block in the 15th Lok Sabha, today started efforts at putting the alliance together again in order to form the next government.

Congress leaders will meet tomorrow to officially endorse Manmohan Singh as prime minister for a second time, after which the party will meet its coalition partners to decide potential new allies.

Prime minister Manmohan Singh on Monday tended the resignation of himself and that of his council of ministers to President Pratibha Patil, who, in turn, issued orders to dissolve the 14th Lok Sabha with immediate effect, paving the way for constitution of the new House.

The UPA, which is 11 seats short of a clear majority in the 543-member House, is believed to have mustered the required support form regional outfits and independents to form the new government at the centre.

With a 100-seat lead against its rival, the BJP-led National Democratic Alliance (NDA), the UPA is in a better position this time around to pick and choose its partner. 

The UPA has emerged the largest block with 261 seats in the Lok Sabha and the President is expected to invite it tomorrow to form the next government at the Centre.

UPA leader and outgoing prime minister Manmohan Singh is believed to have held talks with President Pratibha Patil on the formation of the next government. 

The president is also reported to have consulted constitutional experts, including attorney-general Soli Sorabji, on the way ahead.

The UPA is likely to present letters of support from at least 20 MPs to the president ahead of going for a confidence vote.

The Election Commission led by its new head Navin Chawla was expected to formally submit the list of newly-elected Lok Sabha members to the president today.

The Congress is also likely to retain important ministerial portfolios, including the key ministerial portfolios of finance, trade, defence and foreign affairs.

P Chidambaram is likely to retain the home portfolio while Manmohan Singh is likely to induct the outgoing planning commission deputy chairman Montek Singh Ahluwalia or former PMO advisor C Rangarajan for the finance minister's job.

Rahul Gandhi, the prime choice for the new government, may get a rural job considering his party-building work in rural Uttar Pradesh.

Almost all major regional parties, including Lalu Yadav's RJD and J&K's National Conference (NC), have extended unconditional support to the UPA.

However, UPA partner Dravida Munnetra Kazagam seems not to be in a mood to let go its chances. DMK supremo is leaving for New Delhi tomorrow discuss the issue with Congress president Sonia Gandhi.

The DMK-led front had won 28 of 40 seats it contested, including one in Puducherry. The outgoing ministry had four members from Congress in Tamil Nadu and two from PMK.