China and Taiwan will sign a trade pact later today, which is called the most important development in their relationship for more than sixty years. The Economic Cooperation Framework Agreement, to be signed in the mainland's southwestern city of Chongqing, could unlock massive trade opportunities lying dormant because of existing rules. But many Taiwanese fear it could also chip away at the island's hard-won de facto independence. The deal will confer preferential tariffs, and in some cases zero tariffs, on 539 Taiwanese products from petrochemicals and auto parts to machinery — representing 16 per cent of the island's total export value to China. At the same time, only about 267 Chinese items, or 10.5 per cent of China's export value to Taiwan, will be placed on the early harvest list enjoying zero or falling tariffs.