Trade Ministers and officials from 159 countries have begun formal negotiations at the WTO ministerial meeting at Bali, in Indonesia, in a bid to reach consensus on issues such as food security and trade facilitation. India, which is an important member of the G-33 grouping, is demanding amendments in the WTO draft on agriculture to ensure its food security programme doesn't attract penalties, if subsidy limits are breached. India yesterday made it clear that it would not compromise on the food security issue.