A staunch advocate of mother-tongue education in Hong Kong has criticised the government for putting forward a 'messy' revision to the medium-of-instruction policy to please parents. The Reverend David Cheung Chi-kong said the new arrangements would create in-school labelling and do a disservice to students' learning. Mr Cheung, who served as principal of Carmel Secondary School in Ho Man Tin from the 1960s to 1990, said the new measures were even worse than the controversial decision by the government in 1997 to stream secondary schools into English-medium schools and Chinese-medium ones. Speaking from California, Mr Cheung said: 'Allowing some schools to operate English-medium classes would unavoidably bring more chaos for school management. Worse, it would create within-school labelling. 'A stigma will also be attached to teachers who teach Chinese-medium and English-medium classes respectively. It would bring no benefit for schools, teachers and students,' he said. 'The policy change is completely a mess.' Mr Cheung, who served as an appointed legislator from 1988 to 1991, was at the forefront of a city-wide campaign in the late 1980s to promote mother-tongue education. He took a bold move in 1988 when Carmel Secondary School became the first English-medium school to switch to mother-tongue teaching. Due to strong opposition from unconvinced parents and teachers, the school switched back to teaching in English a year later in a huge setback to Mr Cheung, who resigned in 1990. He then became principal of Pui Ching Middle School, a reputable Chinese-medium school. He has been a missionary since 1991 and is currently president of the Christian Witness Theological Seminary in Concord, California. Mr Cheung said the government was trying to please parents who wanted more schools to teach in English. 'The government is playing the 'public opinion card', but the policy change will do a disservice to students' learning,' he said. 'It doesn't make sense to allow students whose proficiency in English is inadequate to learn certain subjects in English.' He said the government should implement across-the-board mother-tongue teaching from forms one to three, and allow schools to decide which medium to use in higher forms.