Consumer pressure to end plastic packaging in shops could actually be harming the environment, a report says.
Firms are swapping to other packaging materials which are potentially even worse for the environment, the cross-party Parliamentary group warns.
Glass bottles, for instance, are much heavier than plastic so are far more polluting to transport.
Paper bags tend to have higher carbon emissions than plastic bags – and are more difficult to re-use.
The change in packaging materials has been prompted by concern from shoppers about the impact of plastic waste in the oceans.
But the report’s authors say the consequences of using new materials has not been properly assessed.
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Several supermarkets, for instance, are selling more drinks in coated cartons under the assumption that they can be recycled.
In fact, the Green Alliance says, the UK only has the facilities to recycle a third of the coated containers in circulation.