THE middle class is being squeezed, according to a new study which reveals the widest gap between rich and poor in 10 years. The top 10 per cent of households shares 42 per cent of the territory's gross income, while the bottom 50 per cent shares just 19 per cent of the wealth, according to the Hong Kong Social Security Society. The society's analysis of government statistics released last month, on distribution of domestic households, found the economy had benefited the richest minority for the past decade. Among 10 classes of households grouped according to their incomes, only the top class had seen a rise - of 17.75 per cent - in their share in the territory's wealth since 1986. The shares of all other groups had dropped - by 4.61 per cent for the second-richest group and by 31.25 per cent for the poorest. The middle strata, the fifth and sixth-richest groups, saw their shares of the wealth fall by eight per cent to seven per cent and by 11 per cent to 5.7 per cent. The society, which is trying to identify the cause of the phenomenon, said the poverty problem and a widening gap between rich and poor had become too obvious for the Government to ignore. Henry Mok Tai-kee, society vice-chairman and Polytechnic University associate head of Applied Social Studies, called for immediate action. 'Various studies have arrived at the same conclusion: that many people have fallen into the poverty trap except the very rich,' Professor Mok said. 'The Government does not admit there is such a problem because it is worried about having to find a solution to it.' He said Hong Kong could be classed as a Third World city in terms of its disparity of wealth. In another study, which divided households into five median monthly income groups, the society said the poorest saw average incomes rise by 20 per cent, to $5,500 a month. The wealthiest group enjoyed a 61 per cent rise, earning $8,303 more after inflation. 'Even Taiwan and Singapore are doing better than us. Despite a strong economic growth over the years, Hong Kong has adopted a weak social policy,' Professor Mok said. The society urged the future government of the Special Administrative Region to set up a committee to look at poverty and work out a strategy to combat it.