Even before the Senate has taken up the enabling legislation to facilitate the US-India civilian nuclear agreement, one of the strongest critics of the deal has served a notice that he intends to introduce a 'killer amendment' that could scuttle the accord.

Senator Russ Feingold, Wisconsin Democrat, who was one of two Senators on the Senate Foreign Relations Committee who voted against the legislation in July (it was overwhelmingly approved by this panel by a 16-2 margin) on Tuesday said: "We must ensure that as we build a closer strategic relationship with India, one of our most important partners, we do not simultaneously weaken our efforts to stop the widespread proliferation of nuclear weapons."

"The US-India Civil Nuclear Cooperation Agreement has potentially significant ramifications for US national security and the Nuclear Non-proliferation Treaty that must be addressed when this legislation is debated by the full Senate," he said.

In this regard, Feingold said that he intends to offer an amendment to ensure that US nuclear assistance to India is civilian in nature and will not be used to further develop India's nuclear weapons capability, in line with our current treaty obligations.

"I look forward to working with my colleagues to make sure that this agreement is in the best interests of US national security," he added.