CHRONOLOGY - Twists and turns in the India-U.S. nuclear deal

REUTERS - The future of a civilian nuclear deal between India and the United States is pinned on the survival of the government in a vote of confidence on Tuesday.

Here is a timeline of some key developments over the past three years:

* July 2005: Prime Minister Manmohan Singh and U.S. President George W. Bush agree in principle to a landmark civilian nuclear cooperation deal. It reverses 30 years of U.S. policy opposing nuclear cooperation with India because it developed nuclear weapons and never signed the Non-Proliferation Treaty, or NPT.

* March 2006: Bush pays a three-day visit to India during which the two countries agree on India's plan to separate its civilian and military nuclear reactors, a key requirement for the deal to go through.

* Dec. 2006: U.S. Congress overwhelmingly approves the deal. Three other approvals -- from the 45-nation Nuclear Suppliers Group, the International Atomic Energy Agency (IAEA) and a second time by Congress -- are still needed before nuclear transfers to India can actually take place.

* Dec. 2006: Bush signs the law approved by Congress, which makes changes to the U.S. Atomic Energy Act. Analysts say the pact could be fully approved in roughly six months.

* July 2007: The two countries announce finalisation of the deal after months of tough negotiations on a bilateral pact. India had objected to what it said were new conditions in the agreement unacceptable to it.

* Aug. 2007: Text of the bilateral pact, called the 123 agreement, is unveiled simultaneously in both countries. Indian analysts say it meets most of New Delhi's demands, but communist allies of the government coalition threaten to withdraw support over the pact, saying it compromises India's sovereignty. Singh defends the deal as crucial to India's prosperity.

* Oct. 2007: Fraught meetings between the left and the coalition government take place after Sonia Gandhi, head of the Congress party, describes opponents of the deal as enemies of development. A snap election is averted after the government agrees to delay approaching the IAEA.