BAD weather hit construction jobs and kept unemployment last month at an 11-year high of 3.5 per cent. The Government's figures also showed 110,900 people were jobless from June to August, 5,900 more than it had estimated. Unemployment in the trade, catering and transport sectors had eased, but this was partly offset by the four per cent jobless rate in the construction sector. The underemployment rate - for those working less than 35 hours a week - was unchanged from a month ago at 2.5 per cent. Last night, unionists called for an immediate ban on imported workers while officials argued that unemployment was caused by an oversupply of labour brought about by the influx of new immigrants, expatriates and returnees. Statistics show labour supply in the three months to August rose 4.3 per cent over the same period last year, while employment was 2.6 per cent higher. 'Unemployment remains unsatisfactory, but figures show it has started stabilising,' said Government economist Tang Kwong-yiu. He admitted it was unusual to see a rise in unemployment while construction of the new airport was in the full swing. But he added: 'I believe weather is a contributing factor. Sites usually close when there is heavy rain or typhoons.' Hong Kong Federation of Trade Unions vice-chairman Leung Fu-wah blamed the Government for allowing overseas workers to have jobs on airport projects. 'Foreign workers have taken up many of local construction workers' jobs,' he said. And unionist legislator Lee Cheuk-yan branded Mr Tang's comments as 'nonsense' and vowed to put forward a private member's bill to ban importing foreign workers. The Labour Department said the present unemployment rate was a result of job-mismatching, saying there were more than 50,000 job vacancies in the mar-ket.