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 US President George W Bush agree in principle to a landmark civilian nuclear cooperation deal. It reverses 30 years of US 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: US 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 US 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.
* Feb. 2008 - The United States urges India to close the deal before Bush leaves office, saying the deal was unlikely to be offered again under the new administration.
* June 25: The coalition meets with its leftist allies to try and resolve the impasse, but no agreement is reached.
* July 8: The government finds another ally in the Samajwadi Party, who says it will vote in support of the deal.
* July 9:
The left withdraws support for the government, and calls for a vote of no confidence. India submits a draft nuclear safeguards accord to the IAEA governors for approval, despite earlier assurances it would wait to do so until after winning the confidence vote.
* July 10: Agreeing to demands from the left, Singh calls for a vote of confidence in his government. July 21 and 22 are set aside for the vote.
* July 14: The IAEA says it will meet on Aug. 1 to consider India's draft safeguards.