New Delhi, July 2: National Security Advisor (NSA) MK Narayanan is scheduled to meet Samajwadi Party (SP) General Secretary Amar Singh here today, to brief him about the nitty-gritty of the Indo-US nuclear deal, ahead of tomorrow's crucial UNPA meeting.

Tomorrow, the UNPA would decide the future of the third front, and also which way the SP would go in the event of voting in the Parliament over the nuclear deal.

A couple of days ago, Amar Singh had averred that he was not privy to the details of the civil nuclear deal and that he, or his party, has come to know about the deal and 123 Agreement only through his "friends" in Communist parties. He had also said that his party would make its final stance only after getting to know the details of the deal.

The standoff over the nuclear deal between the Congress-led UPA government and the Left parties continues, amid speculations making rounds that the UPA Government might go in for voting over the nuclear deal in the parliament.

Amid hectic political parleys between different parties, Amar Singh had on Tuesday held talks with his CPI-M General Secretary Prakash Karat.

Earlier, after arriving from his vacations in the US on Sunday night, Amar Singh had held deliberations on the nuclear deal with External Affairs Minister Pranab Mukherjee, making the first contact between the SP and the Congress.

The developments over the past few days have given enough hints that the UPA is on the lookout for a replacement of its Left allies, who have been threatening to withdraw support if it moves ahead with the deal.

The Communists are opposing the deal, saying it "compromises India's sovereignty and security" and have threatened to withdraw vital support from the ruling coalition if the government moved ahead with it. (ANI)