New Delhi: The Indian government's communist allies do not support a landmark civil nuclear cooperation deal with the United States, they said yesterday, criticising conditions attached by the US Congress.

Political analysts said Prime Minister Manmohan Singh should still be able to force the deal through parliament, but criticism from both his left-wing partners and the main right-wing opposition party implied stormy weather ahead.

Legislation to allow the United States to sell nuclear technology to India sailed through Congress on Saturday, ending three decades of isolation imposed after New Delhi developed nuclear weapons in contravention of international standards.

The deal has caught the imagination of many in India. But it has also attracted criticism, which has mounted after it was modified in the US legislature.

The Hindu nationalist opposition called the deal "humiliating" on Sunday and said it should be rejected, arguing Washington wanted to cap India's nuclear weapons programme.

Yesterday India's communists, who support the government but remain outside the ruling coalition, also rejected the conditions attached to the deal.

Negates

"Once again the goalposts have been shifted," the Communist Party of India-Marxist (CPM) said in a statement. "This cannot be accepted by India as it negates the most significant, if not all, assurances made by the prime minister to the Indian parliament."

Singh, who first struck the deal with US President George W. Bush in 2005, defused criticism earlier this year by promising parliament he would not accept significant amendments. He may have to go back to the house again.

"An agreement on this basis will seriously undermine the pursuit of an independent foreign policy," the CPM added.

Communists said negotiations on a detailed bilateral pact on nuclear cooperation should be suspended until there had been a full debate in parliament.

Under the legislation passed by Congress, the US president would be required to end the export of nuclear materials if India tests another nuclear device as it did in 1998.