Sonia Gandhi's gracious smile said it all. She had achieved what till then seemed impossible -- bringing Samajwadi Party and Bahujan Samaj Party together.

As Samajwadi Party general secretary Amar Singh thanked Sonia for her luncheon invitation, just a few steps away stood BSP's Lok Sabha leader Rashid Alvi sharing a joke with Lok Janshakti Party's Ram Vilas Paswan.

The credit for Singh and Alvi's presence must also go to SP chief Mulayam Singh Yadav and his BSP rival Mayawati. Both realised their parties' electoral prospects lay in being seen together, at least during the lunch.

The red-carpeted Parliament annexe, where the luncheon was hosted, was also witness to the inimitable style of Laloo Prasad Yadav, a Rajya Sabha member and Rashtriya Janata Dal chief.

Although the lunch was largely meant for opposition leaders belonging to the Lower House, chief Congress spokesman S Jaipal Reddy said Laloo and Amar Singh's presence was in deference to their status as floor coordinators.

Given the importance of the occasion, a day before the 13th Lok Sabha was to be dissolved, lensmen jostled each other to get the best spot.

As flashbulbs exploded and television cameras whirred, the hostess and their guests were captured in bouts of bonhomie.

Also Read BSP, SP, RJD, NCP at Sonia lunch

Garnishing the upbeat mood were gastronomic delights tastefully laid out. There were chicken, mutton and fish dishes with the vegetarians served exquisite preparations like mattar mushroom, paneer pasanda and hari subzi.

Laloo and senior Congress leader Pranab Kumar Mukherjee flanked Sonia.

At a little distance sat former prime ministers Chandrashekhar and Deve Gowda. Gowda, however, appeared a little taciturn.

The irrepressible Somnath Chatterjee of the Communist Party of India (Marxist) praised Sonia for bringing the opposition parties together.

All 'secular' leaders had made it a point to attend barring Ajit Singh, who heads the Rashtriya Lok Dal, and Shibu Soren, who heads the Jharkhand Mukti Morcha. They were said to be busy with 'pre-occupations'. Nationalist Congress Party chief Sharad Pawar was there as was Ramdas Athwale of the Republican Party of India.

RJD's Raghuvansh Prasad Singh, for a change, was not his usual boisterous self, but smiled for the benefit of shutterbugs.

The Congress party's newfound ally in the south -- Dravida Munnetra Kazhagam -- was represented by former central minister T R Baalu. He, however, kept a low profile.

Sonia's ostensible reason for throwing the luncheon was to thank the opposition parties for working with the Congress for the last five years.

"We are greatly satisfied with the kind of response we got and are happy that both the SP and BSP representatives participated in the lunch. It is a remarkable demonstration of unity of secular parties. The exchanges were more friendly, rather than political. It was characterised by great bonhomie," Reddy later told rediff.com

"Having said that, it is not easy for us to say that everybody who came to the lunch would be keen for electoral alliance. There is a problem between the SP and the BSP, they cannot come together easily," he said.

"But their presence at our lunch is an indication of certain things. Firstly, both of them realise the great danger that emanates from the NDA.

"Secondly, both of them realise the need for forging alliance with Congress party in Uttar Pradesh. But to carry both of them is a little difficult but for the rest I thin we have nearly tied up the loose ends," he said.