With the government toying with the idea of a brief winter session of Parliament soon after Diwali, the Left parties have initiated talks with the Third Front on a possible floor strategy against the controversial Indo-US nuclear deal.

CPI-M general secretary Prakash Karat had a meeting with Samajwadi Party chief Mulayam Singh and his TDP counterpart N Chandrababu Naidu [Images] and was said to have discussed floor coordination.

 The parleys came at a time when a growing unease has been witnessed in ruling UPA on the nuclear issue with non-Congress constituents of the alliance having certain reservations and Prime Minister Manmohan Singh [Images] reportedly expressing his disappointment over their attitude.

SP general secretary Amar Singh, at whose residence the meeting was held, described Left parties as "natural allies". The Third Front is christened as the United National Progressive Alliance (UNPA).

The UNPA is for a joint parliamentary committee to be formed on the nuclear deal, a demand supported by the opposition BJP. Reports have it that the government is contemplating a brief session of Parliament next month ahead of Gujarat assembly polls in December and a decision on it is expected this week.

A proposal for a two-week winter session next month is being talked about which would be utilised for the long-delayed discussion on the Indo-US nuclear deal.

The UPA has told Left parties that it was all for discussion on the nuclear deal, but they have to ensure that BJP did not derail the proceedings in Parliament as witnessed during the past sessions.

Meanwhile, top leaders of UNPA met at the residence of former Haryana chief minister Om Prakash Chautala to finetune the Third Front strategy.