Environment Minister Nick Smith faced more questions over his vetoed plastic bag initiative in Parliament today.
Dr Smith caused a stir when he said he was investigating the introduction of a charge on all supermarket plastic bags.
Money generated by the user-pays scheme would go back to the supermarkets, he said.
However, Prime Minister John Key appeared to have a different position on such an initiative when later questioned about it.
"I've made it quite clear to the minister I won't be supporting the introduction of a tax that is paid directly to supermarket chains," he said.
Mr Key agreed initiatives to reduce plastic bag use needed to be investigated.
Labour's environment spokeswoman Nanaia Mahuta asked Dr Smith in Parliament today why he appeared to have backed down from his plan.
He said he was only ever interested in getting the Environment Ministry to investigate ways to reduce usage.
The National Government was about "voluntary measures and good financial incentives" for improving environmental behaviour, he said.
Ms Mahuta said it appeared Mr Key had taken to answering questions for his minister and unsuccessfully attempted to table written questions to Dr Smith which she said had been replied to with advocated answers from the Prime Minister's office.
"The Prime Minister does not answer my written questions," Dr Smith said.
