Banning plastic bags could kill 20 New Zealanders a year, says ACT leader David Seymour.
Local Government New Zealand wants to introduce a levy and the Green Party wants them phased out altogether, but Mr Seymour says studies overseas show there's a risk in forcing people to adopt reusable bags.
"You may end up killing 20 people a year through a lack of food hygiene," he told RadioLIVE this morning.
He says the claim is based on a study by a US university in 2012 showing a switch to reusable bags killed around five people a year in San Francisco. Researchers at George Mason University and University of Pennsylvania linked a rise in E. coli infections and a 46 percent jump in death from foodborne illness to the plastic bag ban.
"People love to demonise plastic, but sometimes we actually have to be serious about the trade-offs we make in public policy."
Mr Seymour thinks it unreasonable to expect people to clean their reusable bags.
"Imagine somebody with their reusable bag sitting in the hot boot of their car with a bit of blood that's seeped out of some steak or chicken – you end up with infections and potentially people dying."
Instead of banning plastic bags, he says there should be heavier penalties for those caught littering them.
The Government's plan is neither a ban nor a levy, instead putting $1.2 million into a new recycling scheme.
"New Zealanders have made a great transition over the last 20 years with the kerbside recycling services - that enables us to recycle the hard plastics - but we now want to tackle the other problems, like plastic bags and bread bags that just end up in a landfill," Environment Minister Nick Smith told Radio New Zealand at the weekend.
The Auckland-based trial will last three years.