There is no guarantee that the Indo-US civilian nuclear deal will go through even if India meets the May deadline for finalising the Interbational Atomic Energy Agency India-specific safeguards as majority of the 53 new members inducted in US Congress are Democrats, US India Political Action Committee Chairman Sanjay Puri said.

Since many of the Republicans in the US Congress during the 'lame duck' session have been replaced by Democrats and also currently there are 53 new members, it may be a challenging situation for the deal to get cleared, Puri told PTI in Mumbai on Thursday.

Referring to the recent US statement that there was still time to say 'now or never', he said the deal has to be cleared by the Congress and not by the administration.

There is a clear shift in balance of power in the American Congress with Howard L Berman taking over as chairman of House Committee on Foreign Affairs, Puri said.

Berman had extracted a commitment from the Bush administration that the Nuclear Suppliers Group's approval to Indo-US deal will be consistent with the Hyde Act.

He said Democrats will never be able to see victory to President Greorge W Bush's foreign policy legacy and its political ramifications.

Of course, Bush is keen to see it through the deal but this may not be shared by many Congressmen, he added.