Professor Chris Coggins, an independent waste and recycling expert who advises the Department for Environment, Food and Rural Affairs (DEFRA), said such policies were allowing supermarkets to pass responsibility for cutting waste on to customers.
The supermarkets should be helping to influence packaging, rather than shifting the problem onto shoppers, he said.
"Supermarkets have the power in terms of what they buy and how it is packaged," he said. "By focusing on the consumer end, they are to some extent diverting attention from what they should be doing."
He added that although plastic bags were a "very visible" form of litter they formed only a small proportion of waste and oil use.
A DEFRA spokesperson said Mr Coggins views did not represent those of the Department.