As he addressed Parliament today, some members of Left parties staged a walk-out, while others made so much noise that MPs who actually wanted to hear what was said had to use their translation headphones. On the right, the BJP has also been critical of the deal, though I tend to think it's more because of political opportunism than anything else: one gets the feeling they wish they'd pulled this off.
Thus far, the Congress Party hasn't seemed seriously concerned about a collapse of the government; no one is yet talking about votes of no-confidence, mid-term polls, or rejiggering the deal to make critics happy.
Are the Communists and others on the left bluffing when they say they will walk away from the Coalition government over this? I tend to think so, though I could be wrong. Indian politics -- with the combination of regional and caste parties in addition to the left/right axis -- is often so complicated, it makes the U.S. system seem laughably simple. Still the Times has a certain wry tone in its summary of where the opposition is coming from:
At one point in Mr, Singh’s speech, the Left parties, which provide crucial support to his Congress-led coalition government, walked out of the house. The Left has opposed the nuclear accord with the United States since it was announced, less over the specific provisions of the accord than over the general principle of closer ties to America.
“We do not share the optimism that India can become a great power with the help of the United States,” Prakash Karat, the general secretary of the Communist Party of India (Marxist), said on Saturday. (link)
(This is where I sniff in Prakash Karat's general direction.)
For those who have kind of let the whole U.S.-India nuclear deal slip past them in recent months, Siddharth Varadarajan has a good point-by-point summary of the agreement here. And the full text of the agreement, released by the U.S. State Department, is here.