The government on Monday explained why it wants to take a gradual approach to getting drinks companies to collect plastic bottles and cartons for recycling, after a lawmaker suggested its initial target isn't ambitious enough.

Under the plans, the bottles and cartons would come with a minimum HK$0.10 rebate and the administration hopes that within eight years, up to 75 percent of the packaging would be recovered.

But there will be four phases to the plan and the initial target is for 30 percent of plastic containers and 10 percent of cartons to be collected, a goal described as "relatively conservative" by lawmaker Chan Yuet-ming.

Environment Secretary Tse Chin-wan said a gradual approach would help drive the programme to success.

"At present in the market, we're talking about a one-percent recovery only. [In the first year], we already require them to increase the [recovery] volume by 10 times," Tse told lawmakers.

"Compared to overseas markets, Hong Kong really has a very wide diversity of sales outlets. It is rather difficult for recovery rate targets to be raised more than 10 percent. We believe that a phased implementation and a phased increase of the recovery target is more appropriate."

The environment chief said the 10-cent rebate is "attractive enough" as an incentive, after several lawmakers raised questions over how sufficient the amount would be in motivating public participation.

"The rebate is at least 10 cents... The scheme operators can always have the discretion to offer a larger rebate," Tse said.

"The recovery target is mandatory and this will put pressure on the operators or the suppliers to recover and collect the amount that would hit the target. Otherwise, the penalty would be on them."

The government intends to introduce legal amendments in the second quarter of this year to establish a framework for Producer Responsibility Schemes.

The proposal for drink suppliers covers containers and cartons with volumes between 100 millilitres and two litres.