A meeting between the Indian government and its communist allies to break a deadlock over a controversial nuclear deal with the United States has been postponed, a senior communist leader said on Wednesday. “The meeting has been postponed for a few days,” Nilotpal Basu, a senior leader of the Communist Party of India (Marxist), the largest of the left parties, told Reuters. “We were informed that the foreign minister is busy with the Syrian president's visit and will be unable to attend the meeting today.” Foreign Minister Pranab Mukherjee is a key intermediary in talks with the left over the proposed civilian nuclear cooperation deal. Syrian President Bashar Al-Assad is currently in India, but it was unclear why the scheduling clash was only discovered at the last minute. Basu could not confirm a new date for the key meeting, but television stations said it would be June 25. The communists have opposed the deal, saying it compromises India's sovereignty and security, and have threatened to withdraw vital support from the ruling coalition if the government moves ahead with it.. Indian shares fell 1 percent after the news of the postponement broke. The communists have allowed the government to discuss but not to finalize an India-specific safeguards agreement with the International Atomic Energy Agency (IAEA), a crucial step in putting the deal into effect. Sources had said India's government would try to persuade the communists during Wednesday's slated meeting to at least allow it to conclude negotiations with the IAEA, something the communists had already indicated they would not agree to. “The window of opportunity is closing and if the dogmatic wax is not cleared from the ears of the communists then the deal is off,” Naresh Kumar, a former Indian envoy to Washington, told Reuters before the meeting was postponed. The agreement is the centrepiece of a new strategic relationship between New Delhi and Washington, and seen as crucial to ending India's isolation in international nuclear trade after it conducted a nuclear test in 1998. The deal is also viewed as vital to the huge energy needs of Asia's third-largest economy, whose growth is being threatened by soaring international crude prices and high inflation. But unless rapid progress is made in the next week or so, the agreement has almost no chance of being finalized before US President George W. Bush leaves office and India heads for elections by next May. Realistically, both governments realize this but are reluctant to publicly abandon a deal in which both have invested heavily, analysts and diplomats say.