The Bogofl, which stands for 'Buy One Get One Free Later' is set to be rolled out by Tesco and is currently being trialled in 470 Sainsbury's stores.
Customers purchasing Bogofl deals receive a voucher at the till which entitles them to a second product free at a later date.
The Sainsbury's trial, which is also designed to encourage shoppers to return to the store, is being carried out on products such as nappies and freshly baked bread. However, c-store retailers say they do not feel threatened by the ploy.
Independent retailer Trevor Merrifield, who owns Winterbourne Post office and Stores near Salisbury, believes most vouchers will probably never be redeemed.
"People have enough trouble remembering to bring bags for life without remembering promotional vouchers, too. I bet that most of the vouchers would never get used," he said.
"I would certainly never run a promotion like this, and I very rarely run Bogof promotions anyway. It's far more responsible, and better for the environment, to run money-off discounts."
Spar retailer Peter Sichel, who has two stores in Holmer Green, Buckinghamshire, also slammed the Bogofl concept. "For starters, this has nothing to do with reducing food waste," he said. "It's just another scheme to drive footfall and increase the supermarkets' margins. I'm not worried about it, though. As long as convenience stores such as mine continue to offer good value for money and friendly personal service, shoppers will come to us. If I worried about everything Tesco did I wouldn't have time to run my business."
Bogofl promotions have also been criticised by fresh produce suppliers who fear they will put them under even greater pressure.