Secretary for the Environment, Transport and Works Sarah Liao Sau-tung also confirmed that the government was considering a levy of 50 cents on each plastic bag at retail level.

But she did not disclose what other measures were being considered, including whether an import duty would be levied on plastic bags.

The retail sector, which is opposing the proposed goods and services tax, is also opposing the green tax, saying it was wrong to "penalize" users of plastic bags.

Liao for the first time confirmed that plastic bags would become the first product to incur a levy under the proposed Eco-Product Responsibility Bill, to be introduced to the legislature later this year.

Based on the government's planning for solid waste management, the tax would be implemented as early as next year. Other products to be levied include rubber tyres, electronic and electrical appliances, and beverage bottles.

According to a government estimate, Hong Kong consumes about 33 million plastic bags a day.