India could put a landmark World Trade Organization deal in jeopardy at hectic negotiations in Geneva after saying that it would withhold support for the agreement unless there was simultaneous progress on resolving a dispute over its food security program. India would like the W.T.O. — which set itself a deadline of July 31 for the deal on the movement of goods across borders — to address its concerns over a cap on subsidies that could limit government stocks of grain that are part of its food program.