Urging Prime Minister Manmohan Singh [Images] to forge a national consensus in support of the Indo-US nuclear deal, a senior South Asian researcher has said a failure to finalise the accord would break the "positive momentum" in the bilateral ties.

"At this juncture, the only hope for salvaging the nuclear negotiations is for Dr Singh to focus his full attention on building a national consensus in support of the deal, explaining how it benefits India's economic, global, and security interests," Lisa Curtis of the conservative Heritage Foundation has said in a Web memo.

"When Leftists in India warn against closer ties with the United States, they miss the broader point: The deal is a tangible demonstration of India's rise on the world stage and will help it to strengthen its scientific position and meet its growing energy needs," Curtis said.

There are "risks" in prolonging the nuclear discussions, Curtis said.

"By next spring, the US will be in the midst of a presidential campaign, and the US legislature will be less inclined to take up the issue with any deliberate speed. It is also uncertain whether a new US president would place the same high priority on getting a nuclear deal passed with India.

The deal has been highly contentious in the United States and has progressed largely because of the political capital invested by President (George W) Bush and his senior advisors. A new US administration might decide to focus its attention on other, less contentious aspects of the US-India relationship," Curtis added.

"Failure to finalise the nuclear deal because of Indian domestic politics would certainly break the positive momentum in the relationship between India and the United States," Curtis said, adding it would also be a "setback" to India's "own reputation as a major world player."