July 18, 2005: Prime Minister Manmohan Singh and US President George W Bush agree on a nuclear deal in Washington.
March 2, 2006: India and the US sign the nuclear agreement during Bush's visit to New Delhi.
March 11, 2006: Communist Party of India attacks government during a special discussion in Lok Sabha terming the accord as an 'unequal' treaty and one which would take India to the 'stable of US global strategy of containing China and Russia'.
July 28, 2006: The Left parties demand threadbare discussion on the issue in Parliament followed by a statement by either the Speaker or Prime Minister Manmohan Singh.
November 16, 2006: US Senate passes the Indo-US nuclear deal.
August 3, 2007: India, US unveil the 123 Agreement.
August 13, 2007: Prime Minister Manmohan Singh makes a suo motu statement on the deal in Parliament
August 17, 2007: Communist Party of India-Marxist general secretary Prakash Karat says that the 'honeymoon (with government) may be over but the marriage can go on'.
September 4, 2008: UPA-Left committee to discuss nuclear deal set up.
February 25, 2008: Left parties say the UPA would have to choose between the deal and its government's stability.
March 3, 2008: Left parties warn of 'serious consequences' if the civilian nuclear deal with the US is operationalised.
March 6, 2008 Left parties set a deadline asking the government to make it clear by March 15 whether it intended to proceed with the nuclear deal or drop it.
March 7, 2008: CPI writes to the prime minister, warns of withdrawal of support if government goes ahead with the Indo-US nuclear deal.
March 8, 2008: The CPI-M says the government should drop the nuclear deal if the UPA-Left Committee does not approve it.
March 14, 2008: CPI-M says the Left parties will not be responsible if the government falls over the nuclear deal.
April 23, 2008: Government says it will seek the sense of the House on the 123 Agreement before it is taken up for ratification by the American Congress.
June 17, 2008: Pranab Mukherjee meets Prakash Karat, asks the Left to allow the government to go ahead with IAEA safeguards agreement.
June 30, 2008: Prime Minister says his government prepare to face Parliament before operationalising the deal.
July 3, 2008: The Left parties decide to work out the timing and modalities of the pullout.
July 8, 2008: Left parties withdraw support to government.