The decision whether to adopt a goods and services tax (GST) will have to wait until a new chief executive is chosen in July, the financial secretary said. The controversial tax was raised as a possibility when Henry Tang Ying-yen took over his post in August 2003, and it was mentioned in his maiden budget last year. It is still under study and officials plan to launch a public consultation on it this year. Also on Mr Tang's tax agenda was a proposed levy on tyres and possible measures to reduce the use of plastic bags, with the polluter-pays principle in mind. But Mr Tang decided against changing the duty on alcoholic drinks, citing the divergence of public opinions on the matter. He said tax deductions for private medical insurance might be considered as part of a larger study on financing of public health services. Mr Tang said public support for a GST has been rising. He cited government polls that found about 40 per cent of the public favoured the tax, up from 30 per cent over the past year. Among those under the age of 30, more than half supported the idea, he said. Mr Tang said he had been encouraged by voluntary public discussions about the tax, although no details - such as the scope of exemptions or impact on operating revenue - had been released. But he said the way forward could not be determined until the new chief executive was elected in July. 'This is the only responsible thing to do. This is a major consultation, and we need a collective decision. This is the reality of the situation.' Mr Tang said the GST, which would take at least three years to implement, would not be just a form of tax, but also a starting point for tax reform. GST concessions and exemptions - on salaries, profits, low-income family needs and tourists - would be likely. On the proposal to levy green taxes, first raised last year, Mr Tang said a levy might be needed to suppress the growth of solid waste. 'In light of overseas experience, I believe that introduction of suitable green taxes can help reduce the growth of solid waste and enhance public awareness of environmental protection.' Mr Tang said the Environment, Transport and Works Bureau had completed an impact assessment on a tyre levy, and was evaluating the cost-effectiveness of different options. The bureau would also study measures to minimise the use of plastic bags and encourage their recycling, he said. An average of 33 million are discarded every day.