The size of the gap between Taiwan and China over the content of the other side's 'early harvest list' will be the key to the signing of an economic cooperation framework agreement (ECFA) between the two sides, a high-ranking official of the Cabinet-level Mainland Affairs Council (MAC) said Saturday. A longer time for negotiations will be needed if the differences are conspicuous, he explained. The MAC official made the comments when asked whether Taiwan and China will be able to ink the planned trade pact in the first half of this year when the top negotiators from each side meet for their fifth round of talks in May. If the two sides fail to clinch the ECFA in May, local industries that have been affected by the recent establishment of a regional trade bloc formed by China and the Association of Southeast Asian Nations will be the most vulnerable, he said. Taiwan and China could initiate negotiations on the ECFA next week at the earliest, with vice ministerial-level officials from both sides likely to be involved in the first round of ECFA talks. Meanwhile, the Ministry of Economic Affairs has listed close to 500 items on its 'early harvest' list for negotiations with China. Some of the sectors considered most likely to be affected by the opening of Taiwan's markets to Chinese competition are included on the list, such as automobiles, petrochemicals, machine tools and textiles. The ECFA must be approved by the Legislative Yuan before it will be able to take effect. 