Ministers at the trade summit in Cancun have begun tough negotiations on agricultural subsidies, the very issue that has caused mass protests and a suicide. Lee Kyang-hae, the former head of South Korea's federation of farmers, stabbed himself to death during the protests, with a friend reported to have said his suicide was "an act of sacrifice" to show his disgust at the policies of the World Trade Organisation (WTO). Groups of farmers from around the world have been amongst the most prominent of those staging protests outside the summit. Government ministers are due to haggle over the highly controversial issue of agricultural policy. The five-day meeting began on Wednesday as several thousand demonstrators clashed with police as they tried to break through a barricade around the site of the WTO meeting.