Warmed up by truant Mamata Banerjee falling in line to back UPA candidate Pranab Mukherjee in the July 19 presidential election, Congress president Sonia Gandhi has sent an invite to her to join the lunch she is hosting at Hotel Ashoka on Wednesday for MPs of all parties supporting his candidature.

Sources said Mamata has been urged to at least ask her Trinamool Congress MPs present in the capital to attend the luncheon meeting where Mukherjee will thank all for the support extended to him if she herself cannot make it. She has been also urged to declare her support to vice-president Hamid Ansari filing nomination for the vice-presidential election on Wednesday.

Many Trinamool MPs are expected to be in the capital in view of a score of parliamentary committees scheduling their meetings on Wednesday to enable the MPs travel to Delhi at parliament's cost and hence the Congress hopes some will attend the lunch. They will, however, have to rush back to Kolkata since they have applied for voting there instead of Delhi, the Trinamool sources said.

Sonia Gandhi has also sent personal invites to Samajwadi Party chief Mulayam Singh Yadav and Bahujan Samaj Party supremo Mayawati, but there was no word about the invitation to Janata Dal(U) president Sharad Yadav or acceptance by him despite him backing Mukherjee in the election. The JD(U) sources said the party is backing Mukherjee as an individual and not as a Congress or UPA candidate to join the pre-poll luncheon meeting.

For that matter, an invite has also been sent out to Jagan Mohan Reddy's YSR Congress for the lunch, though it is another matter that he is in custody and cannot attend himself, but he may send his mother or one of his MLAs to attend.