The promotion starts today, following on from the "hugely popular" Coles campaign last year where shoppers filled plastic pouches with plastic mini-grocery items, received with every $30 spent.

The popularity of the items resulted in shoppers going online to swap them in an attempt to complete the pouches, often prepared to pay amounts far above their original value.

The Facebook page "Coles Little Shop & Woolworths Collectables Swap - Launceston" had more than 1200 members after they were banned from the city's main local buy and sell page.

IN OTHER NEWS:

Coles cited its own customer research to claim 94 per cent of people either kept the items, or gave them to family or friends who were collecting.

Only the packaging can be recycled, via Coles' in-store RedCycle program.

Plastic Free Launceston's Trish Haeusler said it was concerning that on the one hand Coles was reducing plastic bag use, but on the other hand producing plastic toys of negligible usefulness.

"They're very proud of their plastic bag reduction, but then they give shoppers a reward for shopping there in the form of a plastic packaged toy," she said.

"We know the packaging itself can be recycled, but when people are battling to remember to bring back their bags, it's unclear how much of that packaging is being recycled.

"I think we can do better than to give out plastic toys that have no exit plan. Not every toy is going to end up polluting the environment, but in the long-term they aren't going to be recycled.

"That plastic is around forever."

The group is hosting a range of events as part of Plastic Free July with a particular focus on ensuring children learn about plastic pollution.

Ms Haeusler said children were beginning to "grasp this problem" and she hoped parents could "set a good example".

Woolworths' claimed items from its similar Lion King campaign were recyclable in-store.

A spokesperson for Coles said the Little Shop campaign was revived due to the popularity of the first round, where shoppers "told us about the fun they had collecting, swapping and sharing with their friends, families and communities".

"We had many requests to bring it back and customers told us they loved to collect and keep their minis," she said.

"Rather than throwing them out, our customer research shows that of the customers who collected minis last year, 94 per cent have either kept them or given them to family or friends who were collecting.

"The campaign only runs for a limited time and customers who choose to collect them are able to recycle the wrappers at their nearest Coles through our in-store RedCycle program."