The critical meeting between the United Progressive Alliance and the Left parties over the nuclear deal got underway at External Affairs Minister Pranab Mukherjee's residence in the capital on Wednesday evening.

Among those attending the meeting from the government side were Finance Minister P Chidambaram, Defence Minister A K Anthony, Railway Minister Lalu Prasad Yadav, Science and Technology Minister Kapil Sibal and Shipping Minister T R Baalu . The Left parties were represented by the Communist Party of India's A B Bardhan and D Raja, and the CPI-M by Prakash Karat and Sitaram Yechuri. The Revolutionary Socialist Party was represented by T J Chandrachoodan and the Forward Bloc by Debabrata Biswas. Agriculture Minister Sharad Pawar [Images] is away in London [Images] for the felicitation of India's 1983 World Cup winning cricket team.

The feeling within the Congress party is that the meeting will either be the shortest one so far or the longest. Either way, the outcome is being closely watched

Interestingly, ahead of this meeting Lalu Yadav had a separate meeting with Prime Minister Manmohan Singh [Images] to explain why the Rashtriya Janata Dal was supporting the nuclear deal.

Mukherjee and Lalu drove to Dr Singh's residence about an hour before the UPA-Left meeting and were there for over 45-minutes.

During the meeting, a formula aimed at ending the deadlock over the nuclear deal is understood to have been discussed.

The formula is believed to be aimed at suggesting ways to placate the Left parties, which are opposed to the deal, so that the government could survive.

Soon after meeting with the prime minister, Mukherjee and Lalu headed straight for the meeting of the UPA-Left committee at the external affairs minister's residence during which the formula would be considered.

It was the second meeting that Mukherjee had with the prime minister during the day.

While Mukherjee and Lalu were meeting the Dr Singh, leaders of the Left parties went into a huddle to devise their common strategy to be adopted at the UPA-Left meeting.

The meeting was attended by Karat, Bardhan, D Raja, T J Chandrachud, Debabrata Biswas and G Devarajan.

After the deliberations, sources indicated that Wednesday's UPA-Left meeting could be the last as the Left parties had decided to make it clear to the government that they had said what they had to and it was for the government to take a call.

The Left parties have already rejected a compromise formula, which would have allowed the government to finalise the safeguards agreement at the International Atomic Energy Agency.

Earlier in the day, Karat held talks with Mukherjee over the issue following which the CPI-M leader met Samajwadi Party chief Mulayam Singh Yadav.

Additional Reportage: PTI