The Professional Teachers' Union has challenged the Education and Manpower Bureau's claim that no teachers will be made redundant under proposed education reform. Half the roughly 400 aided secondary schools will have surplus teachers, the union's president, legislator Cheung Man-kwong, said yesterday. Redundancies will result from the bureau's plan to reduce the class-to-teacher ratio at senior secondary level from 1:2 to 1:1.9 when the duration of senior secondary education is reduced by one year under the '3+3+4' system. 'How can you expect teachers to support the reform when their jobs are at risk? It will only bring chaos and disasters to schools. Teachers are already having to work 12 hours a day. Their workload will only increase,' Mr Cheung said. He warned that about 20 per cent of aided schools might have more than five surplus teachers. A bureau spokesman said they were seeking the views of schools on class-to-teacher ratios. 'The school sector on the whole will not see a surplus of teachers as a result of the reform,' he said, adding: 'The number of classes and the resultant demand for teachers will not diminish.'