Putting aside the doubts of a set of scientists to deal with another day, Prime Minister Manmohan Singh [Images] on Wednesday called upon the might of the nuclear establishment to help him prepare his defence of the Indo-US civil nuclear deal. A discussion in Parliament on the deal is slated for Thursday.

Although Dr Singh is likely to send a spirited message in favour of the deal, he will also remind lawmakers in India that what is being discussed right now is merely the enabling architecture for the elements of the deal, top sources said.

"What we're talking about is some empowerment to President George W Bush [Images] to enable him to authorise the administration that they can enter into a deal with India. It is only after this that the actual negotiation will begin," the sources said.

They added: "India has its parameters, the US has its own. We have our national interest, the US has its own. No free lunches are available. If we feel our parameters are not being met, we will negotiate till they are."

The sources said the doubts and objections of Indian scientists could not be discounted. "But remember, these scientists belong to an era when denial was the norm of the day where the US was concerned. They had to experience situations where the US put national interest above contractual obligation. They helped build India's nuclear capability in the face of continual technology denial from the US. They built the Param (supercomputer) without any help from anyone. So it is natural for these scientists to feel that if India could do it then, it can do it now."

This is likely to be the trend of the prime minister's speech. On Wednesday, he held a two-hour discussion with Atomic Energy Commission Chairman Anil Kakodkar, Principal Scientific Adviser to the Prime Minister R Chidambaram, National Security Adviser M K Narayanan, the prime minister's Principal Secretary T K A Nair and Foreign Secretary Shyam Saran. Chidambaram had earlier been AEC Chairman.

"This was a formal review meeting," Minister of State for External Affairs Anand Sharma told reporters.

The prime minister, while pointing out that India's concerns have been conveyed to the US, has maintained that New Delhi will not accept any deviation from the 18 July, 2005 understanding reached between him and President Bush.

New Delhi has indicated that it can opt out of the deal if the final US legislation on it does not reflect the spirit of the July 18 statement.

Giving enough hints in this regard, the prime minister told Rajya Sabha on July 27 that "if the US legislative process leads to an end product which is not consistent with what we have committed, that would be the determining factor of what we can do with it".

Conceding that there are "elements (in the bills of the American House of Representatives and the Senate) which are of concern to us", Singh has said "adequate representations have been made to the US government" in this regard and that he himself had taken up the issue with Bush.

"I have an assurance that the US administration will do all it can to say that the parameters, the goal posts of July 18 are not tampered with," he had said.

The scientists, while referring to the "historic" document signed by Singh and Bush last July, on Monday said the US lawmakers, however, have modified, both in letter and spirit, the implementation of such an agreement.